What's new:
-----------

- Handle pthread stacksizes as in GLibc:  Default to RLIMIT_STACK resource.
  Allow to set RLIMIT_STACK via setrlimit.  Default RLIMIT_STACK to value
  from executable header as described on
  https://msdn.microsoft.com/en-us/library/windows/desktop/ms686774.aspx
  Default stacksize to 2 Megs in case RLIMIT_STACK is set to RLIM_INFINITY.

- First cut of an implementation to allow signal handlers running on an
  alternate signal stack.
  
- New API sigaltstack, plus definitions for SA_ONSTACK, SS_ONSTACK, SS_DISABLE,
  MINSIGSTKSZ, SIGSTKSZ.

- New API: sethostname.


What changed:
-------------


Bug Fixes
---------

- Enable non-SA_RESTART behaviour on threads other than main thread.
  Addresses: https://cygwin.com/ml/cygwin/2015-06/msg00260.html

- Try to handle concurrent close on socket more gracefully
  Addresses: https://cygwin.com/ml/cygwin/2015-06/msg00235.html

- Fix fork failing after the parent recovered from a stack overflow.
  Addresses: https://cygwin.com/ml/cygwin/2015-06/msg00384.html

- Fix a crash on 64 bit XP/2003 when opening /proc/$PID/maps.

- Apparently on some Windows systems timezones differ in case
  from the standard.  Fix the tzset tool to check case-insensitive.
  Addresses: https://cygwin.com/ml/cygwin/2015-07/msg00113.html