Features for git log, git show, git tags

## Git Log
![gifrecord_2014-06-06_163733](https://cloud.githubusercontent.com/assets/5219415/3201488/4e77d194-ed88-11e3-81c9-010a941ee6ec.gif)

## Git Show
![git-show](https://cloud.githubusercontent.com/assets/5219415/3204321/396142da-eda7-11e3-9063-5cbf2f095a00.gif)

## Git Tags
![git-tags](https://cloud.githubusercontent.com/assets/5219415/3204327/43d94be0-eda7-11e3-9dfb-5bf63bada59a.gif)

## Todo:
- [x] Make amount commits to show configurable.
- [x] Make the commit selector an abstract class, makes it easy to implement things like Cherry-Pick, Stage-multiple-files and more.