restore class definition using PF information

Restore the so-called "Bad-track" class which disappeared during the migration to GED. The electrons which end up in this category were previously in the "showering class". 
The plots below have been made with RelValZEE 710pre3 samples.
The migration from one class to the other can be seen here:
![h_ele_classes](https://f.cloud.github.com/assets/4553043/2421583/bb597660-ab83-11e3-9cf3-117ee1c8fdd6.gif)
(red is new, blue is default 710pre3; the entries <10 are in the barrel; >=10 in the endcaps)

Even though the regression is using the class and was trained before the fix, it seems that it won't be necessary to retrain it. 
![h_ele_poptrue_showering_barrel](https://f.cloud.github.com/assets/4553043/2421607/25bbff6e-ab84-11e3-9b5f-e7bfc004932d.gif)
![h_ele_poptrue_showering_endcaps](https://f.cloud.github.com/assets/4553043/2421608/25bf4106-ab84-11e3-81c9-904d5b30ad93.gif)
The resolution is actually slightly improved. The statistics have decreased between the two cases, which is normal. 

There are no validation plots for the "badTrack" class, but the inclusive plots is essentially unchanged.
![h_ele_poptrue](https://f.cloud.github.com/assets/4553043/2421621/53dcbc9e-ab84-11e3-981c-b0aff2a015e1.gif)