Add emacs-side caching of completions

Completion-at-point makes multiple calls, really slowing things
up. This change means that subsequent calls immediately return
the same result.
Remove spurious text in docstring
First pass at tooltip support in elisp

Currently we just output it (badly formatted) using (message),
this will be updated to use some nice tooltips
Display tooltips properly. Add keybindings. Bump ver
Fix missing parenthesis in package defn
Add missing (require 'cl)

This could cause problems with byte compiling on other systems
Add another missing (require 'cl)

Responsible for differences between byte-compiled and interpreted
behaviour. See issue #80.
Correct require to 'fsharp-mode-indent

Previous commit missed the point, should have required the
file that contains the macro