Use lens instead of uniplate
Add Vim's gf, <C-w>gf and <C-w>f commands
Use GHC.Generics instead of derive on GHC 7.8
Remove dummyGet and dummyPut from Yi.Utils
Remove list from Yi.Utils
Remove singleton from Yi.Utils
Remove ghc dependency from yi.cabal
Remove unneeded CPP pragma in Data.Rope
Don't use StandaloneDeriving in Yi.Buffer.Basic
Fix build on travis
Use lens in Yi.Buffer.Region
Merge pull request #548 from fread2281/cleanup

Misc Cleanup
Fix src paths in Makefile
Merge pull request #553 from darthdeus/fix-makefile-paths

Fix src paths in Makefile
Merge pull request #547 from jetho/gf-Cmds

Add Vim's gf, <C-w>gf and <C-w>f commands
Show key bindings help in separate window.

In emacs keymap, C-h b now opens a separate window showing the bindings,
more like what emacs does.
Allow multiple lines in minibuffer.

I picked 17 lines allowed because that's what my emacs seems to take
until it starts to open a separate buffer. Perhaps a better heuristic
should be employed but this should be fine unless someone complains. We
could make it customisable.

Closes #477, fixes #478, mention in #485.
Don't use ‘undefined’ for IORef initialisation.

While technically we update it right after anyway, this makes me feel
safer in case any code ever moves around.
update to vty 5.1 interface
correct compile of Yi.Config.Simple when vty is not used