Forward port CMSSW_7_1_X into CMSSW_7_2_X (corrected by hand)

Automatic creation of a pull request did not merge due to a conflict. This pull requests solves the issue by doing the merge by hand. For the record the command I used was:

```
git clone -b CMSSW_7_2_X https://github.com/cms-sw/cmssw
git merge origin/CMSSW_7_1_X
<fix empty space issue>
git commit -a
git push https://github.com/ktf/cmssw HEAD:fix-merge
```

and then I create a pull request. Merging this should also automatically merge #4136.

FYI: @slava77, @davidlange6