mws module: add backward-compatible support for Python 3.3+
update docs for mws's python 3 support
Added descriptions for classes, functions, variables, parameters, and
return values.
Some additional fixes to grammar and sentense structure in the class and
function descriptions.
Merge pull request #2395 from dwightjl/develop

Added documentation for /manage/cmdshell.py. Fixes #2395.
fix len(filter(...)) and move boto.compat import as suggested
swf module: add backward-compatible support for Python 3.3+
fix has_key for python 3 compatibility
cloudwatch module: add backward-compatible support for Python 3.3+
opsworks module: add backward-compatible support for Python 3.3+
Merge pull request #2385 from felixonmars/mws-py3

mws module: add backward-compatible support for Python 3.3+. Fixes #2385.
Merge pull request #2397 from felixonmars/swf-py3

swf module: add backward-compatible support for Python 3.3+. Fixes #2397.
Merge pull request #2400 from felixonmars/cloudwatch-py3

cloudwatch module: add backward-compatible support for Python 3.3+. Fixes #2400.
Merge pull request #2402 from felixonmars/opsworks-py3

opsworks module: add backward-compatible support for Python 3.3+. Fixes #2402.