Updated ability to exclude simple exception handlers

The JavaTddPlugin uses Clover to instrument student code and measure how much of the code is executed by a student's tests.  For a while now, the JavaTddPlugin has supported an option to "exclude simple exception handlers" from coverage analysis, so that coverage of that code isn't required for students to receive 100% code coverage.  Basically, this meant that a catch block that simply catches an exception and ignores it (i.e., the block only contains a comment) or just prints it out (i.e., the block only calls printStackTrace() on the exception) would effectively become invisible to Clover analysis for the purposes of measuring code coverage (at least, if the student never included any tests for that exception condition).

This option is "on" by default, although it can be turned off in the plug-in's options (part of the reusable option set).

Due to some ANTLR-based assignments we've recently run, I extended this behavior in the development version of the plug-in so that simple handlers that just have a "throw" statement--say, that throw a wrapped version of the exception--are also treated as "simple" and excluded from analysis.  I still haven't pushed this change to the publicly released version of the plug-in, but it will go out in the next version (it is currently running on VT's production server).