changing from PXBDetId/PXFDetId to TrackerTopology in CondTools

Replacement of #5646 based on CMSSW_7_3_X_2014-10-09-1400
to make everything more consistent with the comments made by @diguida please do the following (in order to use the RelVal GTs from CondDBv2):
````
from Configuration.AlCa.autoCond_condDBv2 import autoCond
process.GlobalTag.globaltag = autoCond['run2_design']
````
and remove line block 8-13, and line 17