*8784* Introduced object cache for retrieving galleys
*8784* Use object caches
*8771* Submodule changes track
*8786* Introduced tool to start submodules, getting lib code from developer's repository when necessary
*8786* Fixed submodules tool
*8786* Fixed return code
*8786* Fixed for pull requests
*8786* Check for existence of user and branch in submodule message
*8786* Fixed resetting app before the submodule changes track commit
Merge pull request #203 from beghelli/8784-fix

*8784* Add caching to some article galley fetches
Merge branch 'ojs-stable-2_4' of https://github.com/pkp/ojs into uls-install