Remove binding to cabal function from emacs keymap

Fixes #522.
Reduce memory consumption when opening big files.

Yi tries to guess filetype by looking at file contents in String form,
that means an order of magnitude memory overhead. This commit changes
this behavior to looking just at first 1K of file contents.
Actually fix #499.

This time around I don't break movement or Vim searches. I also
replicate emacs behaviour for pressing return.
Workaround for "M-x reload" until we figure out how to make dyre and hint work together.
Update AUTHORS and CHANGELOG for v0.8.
Add issue numbers to changelog bullets.
Add few emacs changes to the CHANGELOG
Fix typo in CHANGELOG
Update accepted lens version range.
Bump version to 0.8.1.
Add vims <C-u>
Add an incompatibility note
Merge pull request #530 from triplepointfive/add-vim-c-u

Add vims <C-u>
Fix opening a directory from CLI with emacs
Use lens for DiredState
Add H, M and L motions
Merge pull request #543 from jetho/VIM_HML

Add H, M and L motions for Vim2
Add optional Settings for Window dependent tests
Update compare and substitute intercalate with unwords
Merge pull request #544 from jetho/hml_test

Add optional Settings for Window dependent tests