Add PB_SYSTEM_HEADER compile time option.

This allows replacing the C99 standard include file names with
a single system-specific file. It should provide all the necessary
system functions (typedefs, memset, memcpy, strlen).

Update issue 62
Status: FixedInGit

pb.h

@@ -8,9 +8,14 @@
 
 #define NANOPB_VERSION nanopb-0.2.1-dev
 
+#ifdef PB_SYSTEM_HEADER
+#include PB_SYSTEM_HEADER
+#else
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <string.h>
+#endif
 
 #ifdef __GNUC__
 /* This just reduces memory requirements, but is not required. */