Add an option to read in a list of points from a .csv file (--fromfile)

[runtingt]

Add an example of using --fromfile in combineTool, proposed in cms-analysis/CombineHarvester#320

[nucleosynthesis]

I know that there is a review of the corresponding code in the CombineHarvester area but given we now have combineTool.py here, that PR should be ported over right?

[anigamova]

@runtingt the EnhancedCombine.py script is now included in Combine see here, do you mind moving the changes from cms-analysis/CombineHarvester#320 to HiggsAnalysis-CombinedLimit repo?

[runtingt]

@anigamova Sure, I was trying to test some changes I'd made in response to @ajgilbert's comments on the harvester PR when I found the bug with the handling of infinities, I'll move these across by the end of the week.

[runtingt]

@anigamova That should be everything moved over now

[ajgilbert]

Just to say that this one looks fine to me now

[kcormi]

I've just tried to resolve the conflicts that appeared in the CI jobs, and moved the test for this specific feature to a different job than the standard counting experiment (just to make it easier to disentangle should one of them be broken).

If we are happy with that, I think its ready to merge.