Simple ssw wrapper for python  

We wrote a simple wrapper for python 2.7 that can be use easily by importing the python class *Aligner*. For now it only works for DNA sequences. The strategy used was similar to the one employed for the c++ wrapper (ie. the returned c structure is converted into a language specific object), with some differences due to specificity of the python language. Doxygen documentation was added and can be parsed using doxypy as an input filter in the dox configuration file.
Inline functions *cigar_int_to_op* and *cigar_int_to_int* had to be moved from ssw.h to ssw.c as simple non static non inline functions since it was impossible to map then with python ctypes librairy.
The makefile was also modified to generate the dynamic library (libssw.so) required for communication with Python. 
Do no hesitate to ask if you want more information.