Add @since tags to some (not all yet) public API functions, to document
in which release they were added (and/or in which release there were
API changes).
Document the @since usage in HACKING.
Also, add Doxygen docs for the functions in version.c.
All frontends will have to include <libsigrok/libsigrok.h> from now on.
This header includes proto.h and version.h, both installed from the
distribution into $INCLUDE/libsigrok/ as well.
The only dynamically changed header is now version.h, which has both
libsigrok and libtool compile-time versions in it.
Uwe Hermann
Bert Vermeulen