* exceptions.cc (setup_handler): Signal event for any sigwaitinfo if it exists

to force signal to be handled.  Zero event here to prevent races.
* signal.cc (sigwaitinfo): Use local handle value for everything since signal
thread could zero event element at any time.  Detect when awaking due to thread
not in mask and set return value and errno accordingly.  Don't set signal
number to zero unless we've recognized the signal.
* sigproc.cc (sigq): Rename from sigqueue throughout.
* thread.cc (pthread::join): Handle signals received while waiting for thread
to terminate.
* cygwin.din: Export sighold, sigqueue.
* exceptions.cc (sighold): Define new function.
* signal.cc (handle_sigprocmask): Set correct errno for invalid signal.
Simplify debugging output.
(sigqueue): Define new function.
* include/cygwin/signal.h (sighold): Declare new function.
(sigqueue): Ditto.
* include/cygwin/version.h: Bump API minor version number.
* include/limits.h (TIMER_MAX): Define.
(_POSIX_TIMER_MAX): Ditto.

winsup/cygwin/include/cygwin/version.h

@@ -236,12 +236,13 @@ details. */
       109: Oh well.  Someone uses reent_data.
       110: Export clock_gettime, sigwaitinfo, timer_create, timer_delete,
            timer_settime
+      111: Export sigqueue, sighold.
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 110
+#define CYGWIN_VERSION_API_MINOR 111
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible