* Makefile.in (GNULIB_TOOL_FLAGS): Do not avoid sigprocmask.
* configure.in (AC_TYPE_UID_T): New dummy macro.
Configure gnulib after adjusting LIBS,
so that gnulib can assume the libraries in LIBS.
* lib/pthread_sigmask.c, lib/sigprocmask.c, m4/signalblocking.m4:
New files, automatically imported from gnulib.
* lib/gnulib.mk, m4/gl-comp.m4: Regenerate.
* src/Makefile.in (LIB_PTHREAD_SIGMASK): New macro.
(LIBES): Use it.