Specify warning for internal only headers that are now installed for use
by extensions.

Go, and likely other language bindings will, need access to create
new combinators. This functionality is currently located
src/parsers/parser_internal.h. Install this header to the system with
dependent headers until a better solution can be found.

Create a pkg-config file and install it to $prefix/lib/pkgconfig

h_sequence need PB_MIN set.

Conflicts:
	src/bindings/python/SConscript
	src/bindings/python/hammer_tests.py

effects throughout, including use of inttypes.h/PRI[ud]64 because printf() is
still stuck in a long world, conversion of %lu to %zu for printing values of
type size_t, and changing/renaming the g_check_cmp* family of functions.

Changed parser test macros so that _parse_ok just checks whether the match succeeded and _parse_match actually checks the resulting parse tree