[EditQueue] WIP: Contents are now versionable

* Modified install.sql for both contents and pages
* Added object type to objectType.xml
* Added AbstractUltimateVersionableDatabaseObject.class.php
* Modified Content, ContentAction and ContentEditor
[EditQueue] WIP: Finished system implementation

* Added page_version table to install.sql
* Added missing foreign keys to install.sql
* Added missing versionable object type for pages in objectType.xml
* Added VersionHandler and VersionCacheBuilder that utilize the needed paradigma
* Modified Page, PageAction and PageEditor to make them version ready
* Modified Content, ContentAction and ContentEditor to use the new VersionHandler
[EditQueue] WIP: Major revamp

* Uses now custom version system
* Fixed many issues arising out of that
* Pages are no longer versionable
[EditQueue] WIP: Introduced unique versionID

* the previous versionID became versionNumber
* versionID is now primary key
[LanguageSystem] WIP: Updated create* and update*

* The create* and update* methods in ContentAction have been updated
* They use the new language system now
[EditQueue] ContentVersion uses new lang system
[EditQueue] Added groupOptions

* Modified userGroupOption.xml
* Added missing language variables
[EditQueue] Fixed cache reset

* Added methods createVersion and deleteVersion to resetCache list
[EditQueue] Uses version now version cache

* Added cache classes
* Modified Content to reflect the changes
Updated README to reflect development status
[LanguageSystem] WIP: Added language entry classes
[LanguageSystem] WIP: Uses versionID now

* Added foreign keys
* Replaced contentID with contentVersionID (basically versionID)
[LanguageSystem] WIP: Fixed file ending
[LanguageSystem] WIP: Added cache classes
[LanguageSystem] WIP: Removed usage of {lang}

* {lang} isn't used anymore for the dynamic contents
* that is only valid for Contents as of now
[LanguageSystem] WIP: Implemented I18n cheating

* The Content*Form controllers use the new language system now
* and thereby cheat on I18nHandler
[LanguageSystem] WIP: Updated updateSearchIndex

* The method updateSearchIndex uses now new language system
[LangSystem] WIP: Updated save, updateSearchIndex

* Updated save method with new language system
* Fixed updateSearchIndex (replaced contentID with versionID)
[LangSystem] Categories use new lang system now
[LangSystem] Fixed cache reset