Update Buildbot URL.
Update tox URL.
Update Travis CI URL because always https.
Use Wayback Machine to resolve a dead link.
Add Qt link.
Update Gunicorn help link.
Update link to Gondor documentation.
Update virtualenvwrapper documentation links.
Update link to 'A Byte of Python'.
Add link to 'Python in a Nutshell'.
Add xmltodict
fix broken tornado link in web.rst
Update brew installation commands
Add back export PATH=/usr/local/share/python:$PATH section
Adding link to Python in a Nutshell
Merge pull request #321 from AnSavvides/master

Adding link to Python in a Nutshell
Merge pull request #319 from JeffPaine/patch-1

Update brew installation commands
Merge pull request #312 from eluck/patch-1

fix broken tornado link in web.rst
Merge pull request #311 from martinblech/master

Add xmltodict to xml scenario.
Update Buildbot URL.