rhbz1148242 - Clear document/locale stats after a copy

Pull Request: https://github.com/zanata/zanata-server/pull/598

Squashed commit of the following:

commit 3e054b4a903b7967da33a074c0a645b6f7ef699a
Author: Carlos A. Munoz <camunoz@redhat.com>
Date:   Thu Oct 2 09:07:37 2014 +1000

    rhbz1148242 - Clear document/locale stats after a copy trans.

    When the stats are reloaded, up-to-date stats will be re-calculated.
Clear document-locale translations stats after a document has been pushed.

This allows Zanata to re-calculate those stats if the document has changed its size or translation state.
rhbz1148641 - disable comment when history popup is due to concurrent conflict
Merge pull request #600 from zanata/stats_after_push

Clear document-locale translations stats after a document has been pushed
Merge pull request #601 from zanata/rhbz1148641

rhbz1148641 - disable comment when history popup is due to concurrent conflict