Matom hotfix

This is an open pull request which contains JM's attempt at fixing bug #54. **DO NOT MERGE!**

At the moment this involves creating a structure jumps_store which stores macro atom probabilities for any macro atoms with densities > 1e13. There is also a last_matom structure which stores only for the last macro atom. There are a number of additions here

* matom.c: matom() additions to check if a probability is stored
* gridwind.c- new function calloc_jumping() dynamically allocates memory for the arrays within structures, similar to the method employed for the macromain ptr.
* wind2d.c - checks for if the density is high enough to be tracked
* python.h - additional variables, definitions and structures.

Feel free to discuss and post suggestions here.