Fix for https://github.com/iElectric/nose-selecttests/issues/5 

This uses the wantFunction and wantMethod instead of prepareTestCase to avoid setUpClass to be called at all
Now using want* nose's extensions instead of prepareTestCase
Updated tests, though test coverage is not great.
Work also with Classes... which weirdly enough measn to not override
wantClass
Bump rev
Added new integration/functional tests using nose PluginTester
Fixed travis config to avoid running the "functional test" tests files
as part of the regular test suite. 

They are called by the PluginTester tests but should not be called
directly) Testing test tools feeling circular at times...
Merge pull request #6 from pombredanne/setup_class_bug

setupClass is no longer called with this fix.