RPM spec file cleanup and bits and pieces:
- Use perl_vendorlib & perl_archlib for better 64bit compat (Jeff Mahoney)
- Clean up Requires, most should be auto-detected
- Restore gtkspell-devel build requirement (and add --without gtkspell option)
- Fix Tcl build requirements to work across more distros
- Fix SILC build requirements to work across more distros

Talking of RPMs, I think we should separate distribution in the release
tag with a period, eg. -0.rh9, -0.fc1, -0.mdk10.0 etc, it would make E-V-R
comparisions a bit more sensible. What do others think?