backup some working bilinear stuff
change default streamline bench file
vlab: add simple trilinear field generator
setup fix: viscid.tools no longer exists, now `setup.py build` works
cython: smaller .c files, and faster compiles

don't type coords in argument list of def'ed functions, this keeps fused types from generating
way too many copies of a given function when we only want 2
add a spherical cap seed generator