[IMP] add starting port as configuration option
[IMP] allow detection of duplicate builds
[IMP] ignore skipped when detecting duplicate
[IMP] rename 'v' in 'context'
[IMP] code refactoring
[IMP] optimizations to runbot controller
[IMP] display duplicate builds
[IMP] improve behavior of skipped/forced builds
[FIX] notifies github for duplicate builds
[IMP] add domain key to the runbot settings screen
[IMP] various improvements
[ADD] add a graph view for runbot builds
Merge pull request #24 from odoo/master-linked-builds-ged


This branch introduce the notion of 'duplicate' builds and use it to reduce the load. Each repository can have a duplicate repository (needs to be explicitely set up) where it will look for possible duplicate builds. If duplicate builds are found, they are linked together and the result of the real one will be used to display data for the duplicate build.

Also, the branch improve somewhat the style of the code, completely refactors the runbot.repo controller (it reduces by about half the number of sql requests done to display the repo page), add options to the runbot settings page (domain key), add a graph view for runbot builds, fixes a few bugs, and probably introduces some new bugs as well.