Doc changes for new pip-requirements

dnspython was added recently to the list of requirments.

This patch completes the change:
1. The new requirement is documented
2. The need for tox --recreate is documented
(assuming there is no way to automate 2 above)

Change-Id: I49f0cb4b01b79dd7cf4329984a2f8416378ebe19
Fixes: Bug #1176627

doc/source/development_guidelines.rst

@@ -41,9 +41,11 @@ To execute the unit tests:
   - `tox`
 
   Remarks:
-  if you installed using: `cd ~/swift; sudo python setup.py develop`,
+  If you installed using: `cd ~/swift; sudo python setup.py develop`,
   you may need to do: `cd ~/swift; sudo chown -R swift:swift swift.egg-info`
-  prior to running tox
+  prior to running tox.
+  If you ever encounter DistributionNotFound, try to use `tox --recreate`
+  or removing .tox directory to force tox to recreate the dependency list
 
 * Optionally, run only specific tox builds:
 

doc/source/development_saio.rst

@@ -29,6 +29,7 @@ Installing dependencies and the core code
      xfsprogs python-eventlet python-greenlet python-pastedeploy
      python-netifaces python-pip`
   #. `pip install mock`
+  #. `pip install dnspython`
   #. Install anything else you want, like screen, ssh, vim, etc.
 
 * On Fedora, log in as root and do:
@@ -37,7 +38,7 @@ Installing dependencies and the core code
      openstack-swift-account openstack-swift-container openstack-swift-object`
   #. `yum install xinetd rsync`
   #. `yum install memcached`
-  #. `yum install python-netifaces python-nose python-mock`
+  #. `yum install python-netifaces python-nose python-mock python-dns`
 
   This installs all necessary dependencies, and also creates user `swift`
   and group `swift`. So, `swift:swift` ought to be used in every place where

doc/source/getting_started.rst

@@ -20,7 +20,10 @@ And the following python libraries:
 * Xattr
 * Nose
 * Sphinx
-* netifaces
+* Netifaces
+* Dnspython
+* Pastedeploy
+
 
 -------------
 Getting Swift