Fix configure.bat

- No need to configure Clownfish
- Unset CL when probing for cl.exe
Fix glitch from IVARS conversion

Fix a glitch in the Windows-specific code.
Fix compilation with C++ compiler
Switch to external Charmonizer

regen_charmonizer.pl now accepts a command-line argument which contains
the path to the Charmonizer tree. If this argument is missing, default
to '../charmonizer' from the Lucy root.
Remove Charmonizer from repo
Regenerate charmonizer.c

Add /MD flag on Windows.