Improve the reliability of determining the Tcl and Tk library version
numbers by only version parsing the library name rather the full path
of the library name. This change solved a bug where the library
version was being parsed from the wine (!) version number that I
happened to be using in my build tree prefix to keep track of various
results for various wine versions.
Add some additional names (with a compact numeric suffix and with no
numerical suffix at all) to search for the itcl and itk libraries.
This change solved a bug where epa_build creates itcl and itk
libraries with compact numerical suffixes on the MinGW/MSYS platform.