Force Tesseroids to use same ratio
Trial recursive implementation for gzz

Getting Float 0 division errors. Not sure where.
Fixed Float division error and switched to queue

Moved the queue inside Cython kernel function. This resulted in a faster
implementation than the Tesseroids recursive one for gzz.
Need to refactor code into smaller functions and reusable part. That's
why I didn't commit the C files as well to avoid clutter.
Pass tesseroid to Cython, not bounds
Separated gzz into funcstions and profiled

Moved some things around and got rid of some Python variable conversions
to get a decent speedup. Got it faster than C.
Need to implement a queue in Cython to be able to release the GIL and
use prange.
Trade collections.deque for a numpy array

Results in ~2x speedup with respect to latest build of Tesseroids.
Could release the GIL for the data loop, making use of prange possible.
Removed nogil block. The queue wont work w prange
Use Cython function pointer to separate kernels

Separated the data loop and redistretization into a cdef function and
pass a pointer to the kernel.
Control what field to benchmark
PEP8 fix on tesseroid test

Few changes to benchmark as well
Moved all fields to new Cython rediscretization

Got consistent speedups with respect to Tesseroids implementation. The
biggest gains are in gzz
Test tesseroid raises exception on queue overflow

Passing queue size as an argument to the Cython functions.
Merge pull request #134 from fatiando/tesseroid-kernels-refactor

Refactor tesseroid kernels