Use correct mode names when g:ctrlp_types is customised.
Use correct mode names when g:ctrlp_types is customised.

Instead of just filtering s:coretypes (which contains descriptive mode
names) based on g:ctrlp_types, change the order of its elements so the
correct mode name is fetched.

Fixes #309.

tschundler/dotfiles,tschundler/dotfiles,tschundler/dotfiles