This incorporates:
2013-09-24 manywarnings: enable nicer gcc warning messages
2013-09-23 warnings: port --enable-gcc-warnings to Solaris Studio 12.3
2013-09-21 timespec: use the new TIMESPEC_RESOLUTION elsewhere
* configure.ac (WERROR_CFLAGS): Omit -fdiagnostics-show-option
and -funit-at-a-time, since manywarnings does that for us now.
This incorporates the following changes:
2013-09-19 stdio: OS X port of putc_unlocked + extern inline
2013-09-19 signal: OS X port of sigaddset etc. + extern inline
2013-09-19 extern-inline: do not always suppress extern inline on OS X
2013-09-17 getgroups: statement without effect
2013-08-28 headers: check that _GL_INLINE_HEADER_BEGIN is defined
