[#718] Use error codes instead of relying on english error messages in datastore
[#718] Move pg error codes in a separate dictionary
[#718] Try to avoid PL/pgSQL since we cannot guarantee that is is activated
Merge pull request #719 from okfn/718-datastore-depends-on-localisation-for-2.1

[#718] Use error codes instead of relying on english error messages in d...
[#537] Remove 'Contrib & Tools' page from documentation

It was moved to GitHub wiki, at https://github.com/okfn/ckan/wiki/Contrib-and-Tools
[#547] Refix main tests after refactor
[#547] Ckanext test fixes
[#547] Pep8 fix
Merge branch 'master' into 547-plugins-love