Bringing over Changes from Google Code

Brad, There are my changes for the following issues:

33 - Make single parameter open() work
34 - Add support for the round function
35 - Make startswith and endswith work
36 - Make quit() and exit() work
37 - Make raw_input() work
38 - Make try / except work

33, 34, 35, and 37 are pretty safe and simple.  My only confusion is that I must be doing something wrong when I add a unit test.   The test passes but I get glitches in either the symtab or parse unit tests.   It might be my environment.

36 - quit() and exit() - are a little more involved because I made a grammar change.  But it is pretty straightforward.  You might want to review if I missed anywhere.

38 - Is likely incomplete.  I have a long comment in the code, commit message, and also in the issue.  In src/compile.js there are several instances of switchCode and suffixCode in src/compile.js - these are the start and end code for the runtime.   I fixed one that I knew how to test because I did not know how to test the other two.  I am guessing the pattern to fix the others would be the same as the one I fixed - but did not want to make any assumptions and introduce a bug later.  So this one needs a bit of review and even some tweaks before merge.

Thanks for taking a look and thanks for keeping the project moving forward.