* Consolidates datum var location
* Move ui_screen to /datum/tgui
* Move focusers to datum.dm. Move fingerprintslast to /atom
* Remove focusers list, makes mobs check if their focus is QDELETED in Life()
* Consolidate use_tag and var_edited into datum_flags
* Revert garbage comment
* Thought I already removed this
* Remove the var_edited preservation
* Removes focus QDELETED handling