Merge tag '1.5.9' into develop

release
Added a method (Pii::appStoreStats()) to retrieve the app store stats from the cache, thus allowing the store to use the Doctrine\Cache\Cache interface. And a composer update.
Current work checkpoint. See diff for details.
removed .idea
Composer dependencies updated.
Composer dependencies updated.
Composer dependencies updated.
Composer dependencies updated.
Composer dependencies updated.
Composer dependencies updated.
Current work checkpoint. See diff for details.
Composer dependencies updated.
Composer dependencies updated.
Composer dependencies updated.
readme update
Fix in Pii to construction of app cache.
update js injects for bootstrap3
release prep
Merge branch 'release/1.5.10'