MAINT: mark SWIG-generated files as binary
ENH: sparse: enable sparsetools to support long long indices

Thanks to peb for the patch.
ENH: sparse: replace intc index type by automatically determined
MAINT: sparse: add a generate_sparsetools.py
TST: sparse: add initial tests for 64-bit indices
BUG: sparse: trigger 64-bit index cast in more locations
BUG: sparse: play safe and do 64-bit cast earlier
BUG: sparse: swap long long -> int64 & int -> int32 in sparsetools

This ensures things keep working as expected also on platforms
with sizeof(int) != 32 and sizeof(long long) != 64
GEN: sparse: regenerate sparsetools files