Skip logic parser. Initial commit
#263 - parser redone
#263 - added friendly error message when invalid clause is provided
using XLF.skipLogicParser to import values into XLF models
Merge branch 'master' into TP263
adding a separate command `linkUp` to use after `parse`. This happens afterwards and ensures that the skipLogicCriteria are linked back to their questions
Throwing some more detailed errors when parameters break things.
changing expression codes to be consistent with model
Fixing karma tests of SkipLogicParser
Merge pull request #62 from kobotoolbox/TP263

Tp263