New public header gpgrt.h as alias for gpg-error.h
* src/gpg-error.h.in (GPGRT_H): New double include protection. * src/Makefile.am (nodist_include_HEADERS): Add gpgrt.h. (BUILT_SOURCES): Ditto. (CLEANFILES): Ditto. (gpgrt.h): New rule.
- Signed-off-by: Werner Koch <wk@gnupg.org>