Added Openloops as a new external package.

Downloads all existing processes and compiles them.
- `openloops.cfg` contains gFortran flag needed.
- Compiles with -Os to try reduce the disk / memory footprint of those
  libraries.
More backporting of debug subpackage support.
Merge pull request #1236 from ktf/backport-debug

More backporting of debug subpackage support.
Merge pull request #1240 from smuzaffar/IB/CMSSW_7_4_X/stable

new config tag with poison plugin and classversion fixes
Merge remote branch 'origin/IB/CMSSW_7_3_X/stable' into IB/CMSSW_7_0_X/stable
Merge remote branch 'origin/IB/CMSSW_7_3_X/gcc491' into IB/CMSSW_7_0_X/stable
Move to cms-externals/thepeg@41e9a26f5ca9659e30e9c27e4dc86e65ecd4a4bd

- New version
- Use tag in place of thepegCommit so that we can actually test PRs
  to thepeg.spec automatically.
Merge pull request #1243 from ktf/new-thepeg

Move to cms-externals/thepeg@41e9a26f5ca9659e30e9c27e4dc86e65ecd4a4bd
Merge pull request #1178 from ktf/openloops

Add openloops external.
Merge remote branch 'origin/IB/CMSSW_7_3_X/stable' into IB/CMSSW_7_0_X/stable
Merge remote branch 'origin/IB/CMSSW_7_3_X/gcc491' into IB/CMSSW_7_0_X/stable
Fix repository for openloops.
Merge pull request #1245 from ktf/fix-openloops

Fix repository for openloops.
Merge remote branch 'origin/IB/CMSSW_7_3_X/stable' into IB/CMSSW_7_0_X/stable
Merge remote branch 'origin/IB/CMSSW_7_3_X/gcc491' into IB/CMSSW_7_0_X/stable
Fix openloops
Merge pull request #1246 from ktf/fix-openloops

Use -O0 to compile openloops
Drop openloops
Merge pull request #1247 from ktf/drop-openloops-73X

Drop openloops
Merge remote branch 'origin/IB/CMSSW_7_3_X/stable' into IB/CMSSW_7_0_X/stable