Patternfly chart styling updates 

* updated pie/donut chart styling with slice margins, 
* updated pie chart label location
* updated highlighter styling

Issue #976
https://trello.com/c/2733Yjls

Before:
![screen shot 2014-12-01 at 3 35 31 pm](https://cloud.githubusercontent.com/assets/1287144/5252852/ee711b6a-796f-11e4-855b-39072d9a62a5.png)

After:
![screen shot 2014-12-01 at 3 34 14 pm](https://cloud.githubusercontent.com/assets/1287144/5252861/fc6f6e88-796f-11e4-8257-7c9f628a3473.png)

Patternfly examples:
![screen shot 2014-12-01 at 3 37 56 pm](https://cloud.githubusercontent.com/assets/1287144/5252872/1631e49a-7970-11e4-9c28-2d76c192283c.png)