- Added a global var WErrorCode similar to errno or RErrorCode.

- New function wsyserrorwithcode(), like wsyserror() for prints the message
  for the specified error code, instead of errno. This is for cases where
  you can't call wsyserror() immediately after the error, but save errno
  code for a later use.

WINGs/ChangeLog

@@ -34,6 +34,10 @@ changes since wmaker 0.61.1:
     2. if new_size is 0, call wfree(old), and return NULL.
     3. if both old is a valid pointer and new_size>0, call realloc.
 - added wstrerror(int errnum) to return the string associated with errnum.
+- added a global var WErrorCode which can hold various error codes
+  (similar to errno or RErrorCode).
+- new wsyserrorwithcode(int error, const char* fmt, ...), similar to 
+  wsyserror(), but printing the message for the specified error code.
 
 changes since wmaker 0.61.0:
 ............................