Tidy up decode-related headers (#280)

Check and reduce some dependency between decode headers

Rename qcbor_decode to qcbor_main_decode to be more clear and help with header backwards compatibility 

Fix a header include backwards compatibility to v1 issue

Fix long lines and trailing spaces


Co-authored-by: Laurence Lundblade <lgl@securitytheory.com>
diff --git a/Makefile b/Makefile
index 2f6c351..5e181dd 100644
--- a/Makefile
+++ b/Makefile
@@ -24,7 +24,7 @@
 CFLAGS=$(CMD_LINE) -I inc -I test -Os -fPIC
 
 
-QCBOR_OBJ=src/UsefulBuf.o src/qcbor_encode.o src/qcbor_decode.o src/qcbor_spiffy_decode.o src/qcbor_number_decode.o src/qcbor_tag_decode.o src/ieee754.o src/qcbor_err_to_str.o
+QCBOR_OBJ=src/UsefulBuf.o src/qcbor_encode.o src/qcbor_main_decode.o src/qcbor_spiffy_decode.o src/qcbor_number_decode.o src/qcbor_tag_decode.o src/ieee754.o src/qcbor_err_to_str.o
 
 TEST_OBJ=test/UsefulBuf_Tests.o test/qcbor_encode_tests.o \
     test/qcbor_decode_tests.o test/run_tests.o \
@@ -54,11 +54,31 @@
 libqcbor.so: $(QCBOR_OBJ)
 	$(CC) -shared $^ $(CFLAGS) -o $@
 
-PUBLIC_INTERFACE=inc/qcbor/UsefulBuf.h inc/qcbor/qcbor_private.h inc/qcbor/qcbor_common.h inc/qcbor/qcbor_encode.h inc/qcbor/qcbor_decode.h inc/qcbor/qcbor_spiffy_decode.h
+PUBLIC_INTERFACE=inc/qcbor/UsefulBuf.h \
+                 inc/qcbor/qcbor_private.h \
+                 inc/qcbor/qcbor_common.h \
+                 inc/qcbor/qcbor_encode.h \
+                 inc/qcbor/qcbor_main_decode.h \
+                 inc/qcbor/qcbor_spiffy_decode.h \
+                 inc/qcbor/qcbor_tag_decode.h \
+                 inc/qcbor/qcbor_number_decode.h
 
 src/UsefulBuf.o: inc/qcbor/UsefulBuf.h
-src/qcbor_encode.o: inc/qcbor/UsefulBuf.h inc/qcbor/qcbor_private.h inc/qcbor/qcbor_common.h inc/qcbor/qcbor_encode.h src/ieee754.h
-src/qcbor_decode.o: inc/qcbor/UsefulBuf.h inc/qcbor/qcbor_private.h inc/qcbor/qcbor_common.h inc/qcbor/qcbor_decode.h inc/qcbor/qcbor_spiffy_decode.h src/ieee754.h
+
+src/qcbor_encode.o: inc/qcbor/UsefulBuf.h \
+                    inc/qcbor/qcbor_private.h \
+                    inc/qcbor/qcbor_common.h \
+                    inc/qcbor/qcbor_encode.h \
+                    src/ieee754.h
+
+src/qcbor_main_decode.o: inc/qcbor/UsefulBuf.h \
+                         inc/qcbor/qcbor_private.h \
+                         inc/qcbor/qcbor_common.h \
+                         inc/qcbor/qcbor_main_decode.h \
+                         inc/qcbor/qcbor_spiffy_decode.h \
+                         src/decode_nesting.h \
+                         src/ieee754.h
+
 src/tag_decode.o: inc/qcbor/UsefulBuf.h inc/qcbor/qcbor_private.h inc/qcbor/qcbor_common.h inc/qcbor/qcbor_decode.h inc/qcbor/qcbor_tag_decode.h
 src/number_decode.o: inc/qcbor/UsefulBuf.h inc/qcbor/qcbor_private.h inc/qcbor/qcbor_common.h inc/qcbor/qcbor_decode.h inc/qcbor/qcbor_tag_decode.h src/ieee754.h src/decode_private.h
 src/iee754.o: src/ieee754.h