WyCS: Improved Error Reporting #411.
When a resolution failure occured during MacroExpansion, there was no
proper error handling.  Instead, a NullPointerException was raised.
This was causing confusing errors in some cases.
WyC: Added test cases for #427.

These test cases all exhibit a similar kind of problem, which is where
the parser mis-recognizes the given list access expression as a cast.
This happens because of the trailing left square, which the parser
mis-reads as the start of a new expression.
WyC: Added Test Cases for #428.

This bug illustrates a problem in the Java backend related to
indirect assignments.
Merge branch 'master' into devel-assert