reflect latest tagged version in configure version
include internal headers in source list

this is required for make dist-* to generate working tarballs
use generic check for nonconforming swprintf arguments

Newer versions of mingw do include the correct API for swprintf. Check for
_CRT_NON_CONFORMING_SWPRINTFS as specified in the swprintf documentation:
http://msdn.microsoft.com/en-us/library/ybk95axf(v=vs.90).aspx