Releng 2 0 - Add Core Temperatures Widget

Add Core Temperatures Widget for pfSense v2.0.2.
Note, the widget depends on the following:
1. proper coretemp.ko, 
2. coretemp_load="YES" entry in "/boot/loader.conf.local" file.

related thread: 
http://forum.pfsense.org/index.php/topic,59193.0.html

Frankly, I'm not sure if this Pull Request (and/or branch) is appropriate.
Please let me if I'm doing it wrong.