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)