OpenRunningTimeout + FIX to events_per_lumi casting

- OpenRunningTimeout: settable, while it was only default value. 
- FIX to events_per_lumi casting, which had effect only when not set and falling on default value


TESTS performed: 

wmcontrol.py --req_file=/afs/cern.ch/user/f/franzoni/public/4antanas/test-GF-2014-11-11.conf --test
wmcontrol.py --req_file=/afs/cern.ch/user/f/franzoni/public/4antanas/test-GF-2014-11-11.conf

wmcontrol.py --release CMSSW_6_2_5 --arch slc5_amd64_gcc472 --conditions POSTLS162_V1::All --version 1 --priority 85000 --time-event 226.13 --size-event 1588 --memory 2300 --request-type MonteCarlo --step1-docID f096a17eea988936256e58fbe02657d4 --request-id B2G-Fall13-00012 --user pdmvserv  --group ppd  --batch 00133 --filter-eff 1.0 --events-per-lumi 100.0 --number-events 75000 --primary-dataset LQLQToTopTau_M_300_Tune4C_13TeV_pythia8_tauola --processing-string POSTLS162_V1 --events-per-lumi 10 --open-running-timeout 56778 --test

wmcontrol.py --release CMSSW_6_2_5 --arch slc5_amd64_gcc472 --conditions POSTLS162_V1::All --version 1 --priority 85000 --time-event 226.13 --size-event 1588 --memory 2300 --request-type MonteCarlo --step1-docID f096a17eea988936256e58fbe02657d4 --request-id B2G-Fall13-00012 --user pdmvserv  --group ppd  --batch 00133 --filter-eff 1.0 --events-per-lumi 100.0 --number-events 75000 --primary-dataset LQLQToTopTau_M_300_Tune4C_13TeV_pythia8_tauola --processing-string POSTLS162_V1 --events-per-lumi 10 --open-running-timeout 56778

a default value is missing