Added tests to demonstrate bug in RAISE_VARARGS (py2.7)
Fixing bug in RAISE_VARARGS.

Was not correctly handling "raise Exception, message" and "raise Exception, message, traceback" syntax.
This was due to the ordering of output that results from calling stack.pop() in a tuple

In [1]: li = ['first', 'second']
In [2]: a, b = li.pop(), li.pop()
In [3]: a,b
Out[3]: ('second', 'first')
Merge pull request #2 from lindzey/exception_args

Tests and bugfix for RAISE_VARARGS
Add Laura to the AUTHORS, and leave a note to ourselves about the dis docs.
Merge branch 'master' of https://github.com/nedbat/byterun