Don't leak getaddrinfo() results
Map WSAEWOULDBLOCK to EWOULDBLOCK. Suggested by Reinhard Max.
Fix [e832d2b08]: unnecessary code in Tcl_SetMaxBlockTime.
Fix [e832d2b08]: unnecessary code in Tcl_SetMaxBlockTime.
Eliminate some redundant Tcl_GetErrno() calls.
Revert [3c0b0bbda6]. If this really is a problem, it needs to get fixed by other means than covering behind void pointers.
Cygwin: In stead of checking whether the win32 part is configured properly, just configure it when needed. 
Always build the stub library first (and - on Cygwin - configure win32 properly just before building the stub library)
Revert [5215b8740c] (Enh [2959069]), as it turns out that -fvisibility=hidden only affects definitions and not declarations. 
Therefore explicitely declaring each MODULE_SCOPE function as  __attribute__((__visibility__("hidden")) is much better. 
Suggested by Stuart Cassoff (Thanks!).
Cygwin: Instead of checking whether the win32 part is configured properly, just configure it when needed. 
Always build the stub library first (and - on Cygwin - configure win32 properly just before building the stub library)
Some formatting
merge trunk