DEP: Deprecate the oldnumeric and numarray modules.

The numarray and oldnumeric modules are deprecated. This is a bit tricky
as raising a DeprecationWarning on import causes an error when tests are
run. To deal with that, a ModuleDeprecationWarning class is added to
numpy and NoseTester is modified to ignore that warning during testing.

Closes #2905
Merge pull request #3422 from charris/deprecate-modules

DEP: Deprecate the oldnumeric and numarray modules.