Adjust 'backspace' in command mode

In vim while in command mode 'backspace' will move the cursor left not delete characters.
Merge pull request #52 from atom/use-absolute-links

Use absolute links to docs
Merge pull request #57 from Tarrant/master

Adjust 'backspace' in command mode
Merge pull request #65 from ctbarna/keymap-enter

"enter" key should move down one line in normal mode.
Merge pull request #68 from ctbarna/ctrl-bracket-extra

Add ctrl-[ keymapping to leave visual mode.
Don't style cursor in mini editors

Previously we accidentally styled the cursor in mini editors which
caused it not to appear in the settings view.

Fixes #67
Merge branch 'master' of github.com:atom/vim-mode
Update CHANGELOG.md
Prepare 0.7.1 release
Merge pull request #72 from zenhob/visual-mode-delete-with-x

visual mode default keybinding: delete with x
Implement 'I' (insert at beginning of line)
Add tests for 'I'
Clarify vision and development best practices
Move left after exiting insert mode
Merge pull request #48 from joefiorini/exit-insert-mode

Move left after exiting insert mode
Add a changelog note for #48
Merge pull request #49 from dysfunction/master

Implement 'I' (insert at beginning of line)
Add documentation for #49
Document existing commands
Merge pull request #71 from jroes/move-to-beginning-of-line

Move to beginning of line