./pear now calls uninstall.  Uninstall functions when no user set

If no user is set in the local git config uninstall would fail
closes #1 

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before
![screen shot 2014-07-04 at 8 28 38 am](https://cloud.githubusercontent.com/assets/2591516/3483545/e11e6602-0390-11e4-8b93-02ee60dad764.png)
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after
![screen shot 2014-07-04 at 8 29 55 am](https://cloud.githubusercontent.com/assets/2591516/3483546/e98e3f4c-0390-11e4-88a4-b4659a99a862.png)