Ca Weight

Allow a user to put in their percentage for a given ca, instead of having to calculate their ca grade themselves. pass me not can now be used like in the screenshot attached
![screenshot 2014-05-22 23 19 16](https://cloud.githubusercontent.com/assets/3747137/3061050/9ea4c94a-e1ff-11e3-8b0d-18169abe1293.png)