Merge pull request #78 from twidi/master

Add the missing 'delete' command to the HashField field
Hightlight python code in the README

Useful for display on github and pypi
Force python code highlighting on documentation

It works the same in RTD, but it's better in github.

Also removed trailing spaces
Add a small README file in the doc directory
Merge pull request #79 from twidi/code-highlighting

Enhance code highlighting in README (and doc, for viewing in github)
Use string when passing floats to Redis (in tests)

It avoids problems with float precision.
Also add footnotes in fields documentation about this
Add argparse and unittest2 requirements to work with python 2.6
Add travis conf for current dev branch only for now
Remove branch whitelist in travis conf, ready for master
Add badges for pypi and travis on README.rst
Add PyPI and travais badges in the doc index file
Correct uses of the old get_pk in the documentation
Add missing "hdel" command on a model to delete many InstanceHashField
Merge pull request #80 from twidi/python2.6+travis

Add conf for travis (+badges), add support for python 2.6, and precisions about floats
Merge pull request #81 from twidi/model.hdel

Add missing "hdel" command on a model to delete many InstanceHashField at once
Replace HashableField by InstanceHashField in documentation