Merge pull request #1 from tum-ens/master

Update forked repository
Result file names contain timestamps abc_YYYY-MM-DD_hh-mm.*
Added comments into source code to clarify commands and equations.
Some questions are left unanswered!
First try: Leave no question unanswered!
changed timestamp format; fixed comp.py incomp with timestamp in result filename
added mimo-example dataset with new Process-Commodty mapping
first uncoordinated model code changes.\n Needs more blueprint prework.
resolve merge conflict in urbs.py
added environmental constraints generally; still global missing
runme.py uses mimo-example, scenarios adapted
updated mimo-example data
completed urbs.create_model changes; fixed get_timeseries
leave no question unanswered (reloaded)
get_constants/get_timeseries now compatible with a single site
renamed commodity colors to process colors
removed results/.NULL; runme.py creates versioned result_dir
get_timeseries now works for environmental commodities
process costs rescaled to throughput (not output!)
added global co2 limit as explicit hack
scenario_co2_limit now correctly uses data['hacks']; result_dir fix