Comment out dependency_links from setup.py

Out of date, but the github master HEAD doesn't work with pip install at present, see https://github.com/wnd-charm/wnd-charm/issues/3
Update install instructions in README
Change pychrm to wnd-charm
Add note that pychrm setup.py needs to be run twice
Merge pull request #13 from manics/update_readme

Update WND-CHARM/PyCHRM links/instructions