Adding a way to fetch all equipments

A search term called ALL_EQS, is introduced in this commit to allow easy
fetching of all hwdoc equipments. Not meant to be used in Web views, it
is mostly added to avoid code duplication, targetting CLI application
using django management commands
Add ticketing to the install documentation

Instructions on how to setup ticketing system. Also update epydoc.conf
Merge pull request #38 from akosiaris/master

Documentation updates, plus a way to return all hwdoc equipments