split qcbor.h into four separate headers (#34)

This is to make it much easier to read the header files.

Backwards compatibility with qcbor.h is retained, but use of qcbor/qcbor_encode.h and qcbor/qcbor_decode.h is preferred now.

Signed-off-by: Laurence Lundblade <lgl@securitytheory.com>
diff --git a/test/qcbor_encode_tests.h b/test/qcbor_encode_tests.h
index 204bdee..e54168a 100644
--- a/test/qcbor_encode_tests.h
+++ b/test/qcbor_encode_tests.h
@@ -38,7 +38,7 @@
 /*
  Notes:
 
- - All the functions in qcbor.h are called once in the aggregation of all
+ - All the functions in qcbor_encode.h are called once in the aggregation of all
    the tests below.
 
  - All the types that are supported are given as input and parsed by these tests
@@ -136,7 +136,7 @@
 
 
 /*
- Calls all public encode methods in qcbor.h once.
+ Calls all public encode methods in qcbor_encode.h once.
  */
 int32_t AllAddMethodsTest(void);