Finish the initial versions of keyval and castext include logics. Add handling...

Finish the initial versions of keyval and castext include logics. Add handling of large scale static content in castext (think MecLib). Add some mixed formating logic and blocks for author level tuning of it.

TODO:
 1. PRTs behave slightly differently, will need to be checked.
 2. Merge the dev-branch here, all the things that went into it this year need to be merged. "@" in keyvals being one of those things.
 3. The inline castext logic needs some documentation, also that block does not exactly react well to wrong arguments.
 4. What do we define as the rules for workign with compiled PRT-function? Can the author access the feedback CASText in feedback-variables and initialsie it into some interestign value before the tree gets traversed, what about the other things, zero node PRTs?