fixed --version in mlaunch. added a test for all tools.
added late evaluation for some operators ($choose, $missing) for more intuitive behavior.
added operators in a separate module below mgenerate.
added DateTimeOperator "$date" or "$datetime". No relative parsing like "-4days" yet.
small fixes to datetime to epoch conversion, and HCI module now understands singular units, like "+1day" instead of "+1days".
Merge branch 'develop' into feature-mgenerate
added __init__ to mgenerate folder.
rewritten the document parsing hierarchy. operators can decide themselves in what order the arguments are decoded, or not at all.

this allows much better control and now $array, $choose, etc behave like intended.