updates from Tao
Merge pull request #122 from dildick/CSC-Trigger-Upgrade-GEM-RPC-SLHC10

updates from Tao
Merge remote-tracking branch 'gem-cmssw/CSC-Trigger-Upgrade-GEM-RPC-SLHC10' into Tao-CSC-Trigger-Upgrade-ME21-SLHC10
1. bugfixed
3. only use Long GEM superchamber
2. add matchGEMPads() to calculate GEMDPhi