Make mcuboot less mynewt style

Remove most of mynewt specific stuff to a separate port package. This
should make mcuboot less "mynewt'y" and slightly easier to port to.

- Mynewt specific stuff moved to boot/mynewt.
- Sample app moved from apps/boot to boot/mynewt.
- Use MYNEWT_VAL macro only on mynewt port.
- BOOTUTIL_* and MYNEWT_VAL() usage moved to MCUBOOT_ defines.
diff --git a/boot/bootutil/src/bootutil_misc.c b/boot/bootutil/src/bootutil_misc.c
index 153d56b..902fe77 100644
--- a/boot/bootutil/src/bootutil_misc.c
+++ b/boot/bootutil/src/bootutil_misc.c
@@ -21,7 +21,6 @@
 #include <string.h>
 #include <inttypes.h>
 
-#include "syscfg/syscfg.h"
 #include "sysflash/sysflash.h"
 #include "hal/hal_bsp.h"
 #include "hal/hal_flash.h"
diff --git a/boot/bootutil/src/bootutil_priv.h b/boot/bootutil/src/bootutil_priv.h
index 85fa178..e8c8a8f 100644
--- a/boot/bootutil/src/bootutil_priv.h
+++ b/boot/bootutil/src/bootutil_priv.h
@@ -20,7 +20,6 @@
 #ifndef H_BOOTUTIL_PRIV_
 #define H_BOOTUTIL_PRIV_
 
-#include "syscfg/syscfg.h"
 #include "bootutil/image.h"
 
 #ifdef __cplusplus
diff --git a/boot/bootutil/src/image_ec.c b/boot/bootutil/src/image_ec.c
index de08b13..fc4c7f0 100644
--- a/boot/bootutil/src/image_ec.c
+++ b/boot/bootutil/src/image_ec.c
@@ -19,9 +19,7 @@
 
 #include <string.h>
 
-#include "syscfg/syscfg.h"
-
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC)
+#ifdef MCUBOOT_SIGN_EC
 #include "bootutil/sign_key.h"
 
 #include "mbedtls/ecdsa.h"
@@ -119,4 +117,4 @@
 
     return rc;
 }
-#endif /* MYNEWT_VAL(BOOTUTIL_SIGN_EC) */
+#endif /* MCUBOOT_SIGN_EC */
diff --git a/boot/bootutil/src/image_ec256.c b/boot/bootutil/src/image_ec256.c
index 1e7354e..615fb9f 100644
--- a/boot/bootutil/src/image_ec256.c
+++ b/boot/bootutil/src/image_ec256.c
@@ -19,9 +19,7 @@
 
 #include <string.h>
 
-#include "syscfg/syscfg.h"
-
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC256)
+#ifdef MCUBOOT_SIGN_EC256
 #include "bootutil/sign_key.h"
 
 #include "mbedtls/oid.h"
@@ -176,4 +174,4 @@
         return -2;
     }
 }
-#endif /* MYNEWT_VAL(BOOTUTIL_SIGN_EC256) */
+#endif /* MCUBOOT_SIGN_EC256 */
diff --git a/boot/bootutil/src/image_rsa.c b/boot/bootutil/src/image_rsa.c
index 4890f46..3ea1a89 100644
--- a/boot/bootutil/src/image_rsa.c
+++ b/boot/bootutil/src/image_rsa.c
@@ -19,9 +19,7 @@
 
 #include <string.h>
 
-#include "syscfg/syscfg.h"
-
-#if MYNEWT_VAL(BOOTUTIL_SIGN_RSA)
+#ifdef MCUBOOT_SIGN_RSA
 #include "bootutil/sign_key.h"
 
 #include "mbedtls/rsa.h"
@@ -143,4 +141,4 @@
 
     return rc;
 }
-#endif /* MYNEWT_VAL(BOOTUTIL_SIGN_RSA) */
+#endif /* MCUBOOT_SIGN_RSA */
diff --git a/boot/bootutil/src/image_validate.c b/boot/bootutil/src/image_validate.c
index 0e78407..9413d31 100644
--- a/boot/bootutil/src/image_validate.c
+++ b/boot/bootutil/src/image_validate.c
@@ -22,17 +22,16 @@
 #include <inttypes.h>
 #include <string.h>
 
-#include "syscfg/syscfg.h"
 #include "hal/hal_flash.h"
 #include "flash_map/flash_map.h"
 #include "bootutil/image.h"
 #include "bootutil/sha256.h"
 #include "bootutil/sign_key.h"
 
-#if MYNEWT_VAL(BOOTUTIL_SIGN_RSA)
+#ifdef MCUBOOT_SIGN_RSA
 #include "mbedtls/rsa.h"
 #endif
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC) || MYNEWT_VAL(BOOTUTIL_SIGN_EC256)
+#if defined(MCUBOOT_SIGN_EC) || defined(MCUBOOT_SIGN_EC256)
 #include "mbedtls/ecdsa.h"
 #endif
 #include "mbedtls/asn1.h"
@@ -96,8 +95,8 @@
     uint32_t off;
     uint32_t size;
     uint32_t sha_off = 0;
-#if MYNEWT_VAL(BOOTUTIL_SIGN_RSA) || MYNEWT_VAL(BOOTUTIL_SIGN_EC) || \
-    MYNEWT_VAL(BOOTUTIL_SIGN_EC256)
+#if defined(MCUBOOT_SIGN_RSA) || defined(MCUBOOT_SIGN_EC) || \
+    defined(MCUBOOT_SIGN_EC256)
     uint32_t sig_off = 0;
     uint32_t sig_len = 0;
 #endif
@@ -106,17 +105,17 @@
     uint8_t hash[32];
     int rc;
 
-#if MYNEWT_VAL(BOOTUTIL_SIGN_RSA)
+#ifdef MCUBOOT_SIGN_RSA
     if ((hdr->ih_flags & IMAGE_F_PKCS15_RSA2048_SHA256) == 0) {
         return -1;
     }
 #endif
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC)
+#ifdef MCUBOOT_SIGN_EC
     if ((hdr->ih_flags & IMAGE_F_ECDSA224_SHA256) == 0) {
         return -1;
     }
 #endif
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC256)
+#ifdef MCUBOOT_SIGN_EC256
     if ((hdr->ih_flags & IMAGE_F_ECDSA256_SHA256) == 0) {
         return -1;
     }
@@ -150,7 +149,7 @@
             }
             sha_off = off + sizeof(tlv);
         }
-#if MYNEWT_VAL(BOOTUTIL_SIGN_RSA)
+#ifdef MCUBOOT_SIGN_RSA
         if (tlv.it_type == IMAGE_TLV_RSA2048) {
             if (tlv.it_len != 256) { /* 2048 bits */
                 return -1;
@@ -159,7 +158,7 @@
             sig_len = tlv.it_len;
         }
 #endif
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC)
+#ifdef MCUBOOT_SIGN_EC
         if (tlv.it_type == IMAGE_TLV_ECDSA224) {
             if (tlv.it_len < 64) { /* oids + 2 * 28 bytes */
                 return -1;
@@ -168,7 +167,7 @@
             sig_len = tlv.it_len;
         }
 #endif
-#if MYNEWT_VAL(BOOTUTIL_SIGN_EC256)
+#ifdef MCUBOOT_SIGN_EC256
         if (tlv.it_type == IMAGE_TLV_ECDSA256) {
             if (tlv.it_len < 72) { /* oids + 2 * 32 bytes */
                 return -1;
@@ -193,8 +192,8 @@
             return -1;
         }
     }
-#if MYNEWT_VAL(BOOTUTIL_SIGN_RSA) || MYNEWT_VAL(BOOTUTIL_SIGN_EC) || \
-    MYNEWT_VAL(BOOTUTIL_SIGN_EC256)
+#if defined(MCUBOOT_SIGN_RSA) || defined(MCUBOOT_SIGN_EC) || \
+    defined(MCUBOOT_SIGN_EC256)
     if (!sig_off) {
         /*
          * Header said there should be PKCS1.v5 signature, no TLV
diff --git a/boot/bootutil/src/loader.c b/boot/bootutil/src/loader.c
index dc6d9cb..95a1572 100644
--- a/boot/bootutil/src/loader.c
+++ b/boot/bootutil/src/loader.c
@@ -1265,7 +1265,7 @@
 
     switch (swap_type) {
     case BOOT_SWAP_TYPE_NONE:
-#ifdef BOOTUTIL_VALIDATE_SLOT0
+#ifdef MCUBOOT_VALIDATE_SLOT0
         rc = boot_validate_slot(0);
         assert(rc == 0);
         if (rc != 0) {