Order cdef classes by inheritance before generating the code.
Merge pull request #223 from nnemkin/cdef_class_order

Order cdef classes by inheritance before generating the code.
use unique 'objstruct_cname' instead of 'name' when sorting extension types
add assertion, just in case
Undo sorting types by inheritance until we figure out what's up with Sage.
Revert "Undo sorting types by inheritance until we figure out what's up with Sage."

This reverts commit 12d7dbb301851508af7950fbb4307a1d5b2af615.
update version to 0.19.1rc1