editors/vim: Flavorize and consolize

[adamw]

Summary

This makes some significant changes:

• Convert slaves to flavors (slave removal not included in this patch)
• Make vim be the console package (editors/vim@gtk3 = vim-gtk3)
• Only python bindings in the default package (I'm not aware of anything that actually uses perl or ruby bindings)
• Drop support for py27
• Drop cscope and ctags-exuberant from the default package

Test Plan

@portmgr: I haven't flavorized before, so I could use your eyes on this patch.

My box is simply way too underpowered to test gtk2 and gtk3. If someone can testport them, that'd be a huge, huge help.

To test -tiny: cp vim-tiny/pkg-plist vim/pkg-plist-tiny