Merge pull request #8 from ametad/master

P3Page::getMenuItems() returns sub-menu-structure if a menu-item has children
fixed delete link createUrl
updated foreign key constraints
updated translation CRUD
enhanced access control security
added missing view
moved migration data to separate folder
updated CRUD views
added translation skeletons
added added migration for menu renaming
minor
fixed deps
fixed typo
majort usability upgrade

added add child page function
improved CRUDs
updated UI
fixed access filter, UI update
updated menu rendering
added isActiveParent method
cleanup
enhanced active page detection, updated label