Big commit - added 200 soluble pdb files (in pdb dir) for testing. 
Also commiting my code in pdb_reader.py which handles the loop
extraction via DSSP/BioPython if a given PDB file isn't annotated.
Also updated the gitignore file - we don't want to have the dssp
executable tracked in the LSP source control; nor do we want
pydev/eclipse settings and I added a line for something called DS_Store
which is a silly Mac thing that gets generated in the background.