Infiniband patch for OpenMPI < 1.8.6

[boegel]

wrapper PR for #1678 by @ULHPC / @sylmarien

this basically only fixing conflicts with current develop so the PR can be merged

[hpcugentbot]

Refer to this link for build results (access rights to CI server needed):
https://jenkins1.ugent.be/job/easybuild-easyconfigs-pr-builder/3756/
Easyconfigs unit test suite PASSed (see https://jenkins1.ugent.be/job/easybuild-easyconfigs-pr-builder/3756/console for more details).

This pull request is now ready for review/testing.

Please try and find someone who can tackle this; contact @boegel if you're not sure what to do.

[boegel]

Test report by @boegel
SUCCESS
Build succeeded for 26 out of 26 (26 easyconfigs in this PR)
Linux SL 6.6, Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GHz, Python 2.6.6
See https://gist.github.com/2935169497922b494b23 for a full test report.

[boegel]

reviewed version of #1678, going in, thanks @sylmarien (and @besserox for the patch ;))!

[boegel]

Test report by @boegel
SUCCESS
Build succeeded for 26 out of 26 (26 easyconfigs in this PR)
Linux SL 6.6, Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GHz, Python 2.6.6
See https://gist.github.com/2aacc2319838de5eff39 for a full test report.

[boegel]

I was forced to revert this for EasyBuild v2.2.0 via #1798, since this changes causes runtime segfaults for builds that use OpenMPI (see #1797 for example).

[boegel]

alternative patch for this: #1799, #1800