Don't try to highlight git commit errors

Causes problems when using external editor to write commit message
Further improve git aliases

- Replace la (list aliases) with 'aliases' alias (taken from git wiki)
- Restore ca (commit all) alias (seems I do actually use this)
- Use external commands to format output from for-each-ref aliases
- Rename mru to recent (lists recently active branches)
- Add new mru alias to list recently used/checked-out branches
- Add wc alias for log of what changed (sort of like git whatchanged)
- Remove previous branches alias, and rename heads alias to branches
- Add some default arguments for git related bash aliases