Update to git plugin for "short graph" mode. Command: glp (git log pretty)

New command in git plugin:  glp

outputs a history of repo, who did what, with the notes, and a wee dependancy graph... (with obligatory terminal colours where applicable!)

Example output:
```
* commit f5d594baeae84fa2925284f68c636417dec9482c
| Author: D. Rimron <d@REDACTED.com>
| 
|     Updating installer to use our own repo
|    
*   commit 3552423de3d5ae439dc815b7f9c4cbeab3fbebe8
|\  Merge: 279cf27 527355e
| | Author: Robby Russell <robby@REDACTED.com>
| | 
| |     Merge pull request #429 from mhitza/master
```

-Dx