Cat Toggle

I'm not even sure this pull request should exist as i'm not completely thrilled at how I handled unbinding of the keyboard_cat events.  It does seem to work with minimal testing but i'd appreciate any feedback at how to unmap the events as iunmap doesn't seem to work after a inoremap has already occured.  See if it works for ya.  I don't really know how to vimscript.

- leader ew will turn keyboard cat "off"
- simply doing another playmeoff will start from the beginning of the new file