Replay multi-character maps by introducing a buffer delay

Save and replay characters that would otherwise be "lost"
Fix one place that needs to handle new multi-char buffer
Fix cursors getting out of sync when entering/exiting insert mode

Also simplify revert_mode function
Update README
fix two minor bugs
Remove lag when changing cursors (<C-n> etc)
Much simpler, cleverer method
Make insert-mode mappings work
Only do insert-mode mappings in insert mode
Fix default value of g:multi_cursor_insert_maps
Only wait for a multi-key mapping if we failed to replay *everywhere*
Be a little smarter about when we call getchar
Fix repeated commands (like `5w`) with multiple cursors
Have colon exit multi-cursor, rather than just breaking things
Make normal-mode multi-key maps configurable as well

Otherwise motion commands that don't replay do weird things.
tweak readme
less hacky fix for out-of-sync issue when exiting insert mode
Fix typing a ':' in insert mode with multiple cursors
Don't swallow keypresses following : in high load

We exit immediately, so we never get a chance to use them.
Merge pull request #3 from eapache/multi-char-maps

Replay multi-character maps