Make explicit the requirement for Emacs 24

See #41
Merge pull request #42 from purcell/patch-3

Make explicit the requirement for Emacs 24
Major mode for Idris log buffers

Includes faces for highlighting timestamps and levels, plus View mode in
log buffers.
Add command and menu item for viewing compiler log
Merge pull request #43 from david-christiansen/better-log

Major mode for Idris log buffers
Add command for easy insertion of _|_
Merge pull request #46 from david-christiansen/insert-bot

Add command for easy insertion of _|_