Windows7 command: set http_proxy and bypass

1. Specify multiple no_proxy hosts separated by commas, not semicolons.

2. Also, by convention Windows/DOS environment variables should be all uppercase (although I would hope most tools would ignore case).

   set NO_PROXY=localhost,127.0.0.*

From the Python 2 docs for urllib:

The no_proxy environment variable can be used to specify hosts which shouldn’t be reached via proxy; if set, it should be a comma-separated list of hostname suffixes, optionally with :port appended, for example cern.ch,ncsa.uiuc.edu,some.host:8080.