#3553: DeprecationWarning when running tests (compile_rule)

Add: +SKIP for doctest.

I'm not sure if that's ok.  More clever way is to skip DeprecationWarning's while running doctest's (and, may be usual tests) - we don't want to break deprecated stuff, right?  If the feature is not removed - it still be supported.

Perhaps,
http://code.google.com/p/sympy/issues/detail?id=3451
should be tagged with DeprecationRemoval.