Started working on configure.ac for MSYS build.
Merge from trunk.
configure.ac done, not tested yet.
configure runs to the end, need to analyze differences vs config.nt.
Merge from trunk.
Minor fixes and improvements in configure.ac.
Merge from trunk.
Fixed configure.ac and headers in nt/inc.  Emulated functions not handled yet.
Conclude what can be done about headers, macros, and compiler switches.
What is left is missing and replaced functions provided by Emacs.
Merge from trunk and resolve conflicts.
Made references to nt/inc absolute, so out-of-tree build could be supported.
Fix the gettimeofday_timezone test.
Use 'restrict' in gettimeofday arguments, and make ms-w32.h compatible.
Added nt/mingw-cfg.site, first few vars defined on it.
Fix CLASH_DETECTION and 'not needed' result for fdopendir.
Handled fstatat and fsync, fixed fdopendir.
Finished first cut of mingw-cfg.site.
Finished with config.nt diffs.  Problem with mmsystem.h remains.
Incorporated m4/stdalign.m4 fix from gnulib.
Merge from trunk.