on MinGW32, use compiler provided [v]snprintf
release thread handle
Merge pull request #105 from pijyoi/master

win32 fixes
Updated for next release 1.3.3
Fixed #ifdef order in header file
Added printf formatting to send/sendm, deprecated sendf/sendfm
Added zsys class for non-portable file system functions
Cosmetic change
If zctx_interrupted is non-zero, does not install signal handler
Merge pull request #106 from hintjens/master

Started zsys class for various non-portable system functions
Make zctx_destroy restore original sighandler
Merge pull request #107 from felipecruz/feature/context_signal_test

Make zctx_destroy restore original sighandler
Fixed signal handling
- non-portable signal code moved to zsys
- zsys_handlers_set (NULL) to prevent CZMQ installing its handlers
- note: no longer a side-effect of setting zctx_interrupted to 1
- zsys_handlers_reset () at exit to restore default handlers
Merge pull request #108 from hintjens/master

Refactored signal handling
Was wrongly saving default handlers
Merge pull request #109 from hintjens/master

Was wrongly saving default handlers