WIP: cython stuff
WIP: fail at fused data types
MAINT: more conversions to give int32 indices instead of int64
MAINT: remove cython code replaced by fused types
MAINT: remove debug prints and more replaced code
MAINT: clean up more leftover debugging junk
Merge pull request #76 from argriffing/cython-int

do not feed long indices when sparse code expects int32