updated plot1DScan and plotImpacts with cmsstyle

[kasharko]

Made plot styles (for plot1DScan.py and plotImpacts.py) dependent on cmsstyle package, to be able to propogate any recent changes in official CMS recommendations. Precisely changed plotting style, legend calls and colors.

[amarini]

what happens if CMS style is not installed?
we should make sure that the scripts works also w/o it or with some other custom choices.

[anigamova]

Indeed, is this should stay open until this question is resolved. But we discussed having cmsstyle included in the future CMSSW releases, and add install cmsstyle to the combine container environment

[anigamova]

Requests from the CAT meeting today:

• check if cmsstyle is available, otherwise use to gStyle (previous implementation)
• add luminosity label to the plot1DScan.py
• change the Y axis label to q and/or add a command line option, defaulting to q
• add an option to control CMS logo position (inside or outside the plot)