Implement jumping back using ' and ` marks in Vim2
Add tests for unjumping marks
Merge pull request #525 from exlevan/marks

Implement jumping back using ' and ` marks in Vim2.
Hiding moveTo from Control.Lens is no longer necessary.
Fix build with ghc-7.8.1.
Merge pull request #526 from ethercrow/alex78

Fix compilation with ghc 7.8.
Remove some laziness from Vty frontend.

The only difference I managed to observe after that is that yi eats less
memory. Vty frontend appears to work fine. If it actually breaks
something, feel free to revert this commit.
Remove binding to cabal function from emacs keymap

Fixes #522.