Adapt script and instructions for alt config.h
diff --git a/configs/README.txt b/configs/README.txt
new file mode 100644
index 0000000..7527fdb
--- /dev/null
+++ b/configs/README.txt
@@ -0,0 +1,24 @@
+This directory contains example configuration files.
+
+The examples are generally focused on a particular usage case (eg, support for
+a restricted number of ciphersuites) and aim at minimizing resource usage for
+this target. They can be used as a basis for custom configurations.
+
+These files are complete replacements for the default config.h. To use one of
+them, you can pick one of the following methods:
+
+1. Replace the default file include/polarssl/config.h with the chosen one.
+
+2. Define POLARSSL_CONFIG_FILE and adjust the include path accordingly.
+   For example, using make:
+
+    CFLAGS="-I$PWD/configs -DPOLARSSL_CONFIG_FILE='<foo.h>'" make
+
+   Or, using cmake:
+
+    rm CMakeCache.txt
+    CFLAGS="-I$PWD/configs -DPOLARSSL_CONFIG_FILE='<foo.h>'" cmake .
+    make
+
+Note that the second method also works if you want to keep your custom
+configuration file outside the PolarSSL tree.
diff --git a/configs/config-mini-tls1_1.h b/configs/config-mini-tls1_1.h
index 81a95f0..f6016e8 100644
--- a/configs/config-mini-tls1_1.h
+++ b/configs/config-mini-tls1_1.h
@@ -2,10 +2,17 @@
  * Minimal configuration for TLS 1.1 (RFC 4346), implementing only the
  * required ciphersuite: TLS_RSA_WITH_3DES_EDE_CBC_SHA
  *
- * Can be activated with:
- *      scripts/activate-config.pl configs/config-mini-tls1_1.h
+ * See README.txt for usage instructions.
  */
 
+#ifndef POLARSSL_CONFIG_H
+#define POLARSSL_CONFIG_H
+
+/* System support */
+#define POLARSSL_HAVE_ASM
+#define POLARSSL_HAVE_TIME
+#define POLARSSL_HAVE_IPV6
+
 /* PolarSSL feature support */
 #define POLARSSL_CIPHER_MODE_CBC
 #define POLARSSL_PKCS1_V15
@@ -44,5 +51,4 @@
 /* For testing with compat.sh */
 #define POLARSSL_FS_IO
 
-/* marker for activate-config.pl
- * \} name SECTION: PolarSSL modules */
+#endif /* POLARSSL_CONFIG_H */
diff --git a/configs/config-psk-rc4-tls1_0.h b/configs/config-psk-rc4-tls1_0.h
index 1da378c..260b713 100644
--- a/configs/config-psk-rc4-tls1_0.h
+++ b/configs/config-psk-rc4-tls1_0.h
@@ -2,10 +2,16 @@
  * Custom compact configuration for TLS 1.0 with PSK and RC4
  * Distinguishing features: no bignum, no PK, no X509.
  *
- * Can be activated with:
- *      scripts/activate-config.pl configs/config-mini-tls1_1.h
+ * See README.txt for usage instructions.
  */
 
+#ifndef POLARSSL_CONFIG_H
+#define POLARSSL_CONFIG_H
+
+/* System support */
+#define POLARSSL_HAVE_TIME
+#define POLARSSL_HAVE_IPV6
+
 /* PolarSSL feature support */
 #define POLARSSL_KEY_EXCHANGE_PSK_ENABLED
 #define POLARSSL_SSL_PROTO_TLS1
@@ -28,5 +34,4 @@
 #define POLARSSL_SSL_SRV_C
 #define POLARSSL_SSL_TLS_C
 
-/* marker for activate-config.pl
- * \} name SECTION: PolarSSL modules */
+#endif /* POLARSSL_CONFIG_H */
diff --git a/configs/config-suite-b.h b/configs/config-suite-b.h
index 2bfb0e1..7f085f4 100644
--- a/configs/config-suite-b.h
+++ b/configs/config-suite-b.h
@@ -1,10 +1,17 @@
 /*
  * Minimal configuration for TLS NSA Suite B Profile (RFC 6460)
  *
- * Can be activated with:
- *      scripts/activate-config.pl configs/config-mini-tls1_1.h
+ * See README.txt for usage instructions.
  */
 
+#ifndef POLARSSL_CONFIG_H
+#define POLARSSL_CONFIG_H
+
+/* System support */
+#define POLARSSL_HAVE_ASM
+#define POLARSSL_HAVE_TIME
+#define POLARSSL_HAVE_IPV6
+
 /* PolarSSL feature support */
 #define POLARSSL_ECP_DP_SECP256R1_ENABLED
 #define POLARSSL_ECP_DP_SECP384R1_ENABLED
@@ -44,5 +51,4 @@
 /* For testing with compat.sh */
 #define POLARSSL_FS_IO
 
-/* marker for activate-config.pl
- * \} name SECTION: PolarSSL modules */
+#endif /* POLARSSL_CONFIG_H */