added Problem node and insertion for expected tokens
improved names for missing identifiers
added possibility to recover from specifications of missing types
removed commented lines
added ProblemReporter infrastructure
improved(?) multiple problem reporting
why shouldn't parameters be allowd to be unused?
removed warnings
improvements and experiments
possibility to "insert" expected tokens
fixed error
improved toString
refactored
some corrections and documentation improvements
implemented some equals methods for literals
added test target to buildfile
fixed some positioning issues
whitespaces
corrected position of [] operator expressions
further test case