Mark first batch of really slow tests.
Mark some more tests as slow and do some cleanup while there.
Fix huge amount of whitespace in between function arguments in tests.
Tag a bunch of slow tests according to the linux timings.
Attributes on a class can be a source of problems.
Some changes following review
Merge pull request #1723 from abergeron/tag_slow

Tag slow tests
Fix unpickling of Elemwise op since openmp changes.
Merge pull request #1733 from nouiz/fix_unpickling

Fix unpickling of Elemwise op since openmp changes.