Implemented missing loops
Added loops; moved some tests to ReferenceTests
Avoid NPE when using string conversion, simpler code
Finished implementation of loops
Added tests for break/continue
Corrected BreakInForLoop test
Added FlowControlException class hierarchy and changed code
Implemented throwing of Continue/BreakException on statements
Implemented Continue/BreakException handling
Modified tests to show that ouput in loop body works
Adjusted continue/break behavior with scripts
Corrected execution of trap bodys
Fixed c# method invocation bug with null, enabled tests
Use same ExecutionVisitor for loops and conditions

This avoids problems with unwritten values if an exception interrupts
the execution
Added tests I forgot to commit
Merge pull request #314 from sburnicki/method_with_null

Fixed c# method invocation bug with null, enabled tests
Merge pull request #313 from sburnicki/do_while

Implementation of missing loops, break, and continue
Merge pull request #312 from sburnicki/ArrayToStringFix

Avoid NPE when using string conversion, simpler code