* regex-posix.c, regex-posix.h: New files. (Some code
is taken liberally from rx/rgx.c in the old Guile dist.)
* init.c: Include regex-posix.h.
(scm_boot_guile_1): Call scm_init_regex_posix.
* Makefile.am (EXTRA_libguile_la_SOURCES, modinclude_HEADERS):
Add regex-posix.[ch] sources.
* Makefile.in: Regenerated.
* scmconfig.h.in: Add HAVE_REGCOMP macro. (automake is supposed
to do this automatically? It didn't for me, bleh.)
