allow git command to be set with 'git_gutter_git_command'
Use the encoding helper in diff

Uses the encoding helper for cleaning up encodings in the diff.
Merge pull request #1 from RazerM/FixST2

Fix ST2 compatibility for gutter icons.
Change version check to check for build 3014
Merge branch 'master' of github.com:magnuf/GitGutter into magnuf
Merge branch 'master' of github.com:akirk/GitGutter into akirk
DRY up that icon path biz and conform to PEP8 (lines over 80)
Add settings framework
Implement updated git binary path setting.
Change live_mode implementation.

Requires existing settings to be changed to new format, see README
Add default settings file
Menu items for default and user settings.
Add details of new settings into README