Fixes #1338: Bring back a label that got lost
Task #1333: Remove cmake git tag reading
Fixes #1334: Only unequip item if the sell/drag action is actually successful
Do not load (0,0) on new game
Simplify new game movie player
Clear choices when dialogue starts

This is usually not needed, because it is not possible to exit dialogue while in a choice. However you can still exit dialogue by loading a different savegame.
Fix not returning to main menu on failed loads when using quickload
Only run --script-run commands when bypassing the menu

Running them while no game is started yet is dangerous, and also leaves bits and pieces of state (e.g. in LocalScripts for scripted items added to inventory) that will not get cleaned up properly when a game is loaded (since when no game was previously running, no cleanup is performed). As a result, dangling MWWorld::Ptrs were left in LocalScripts.
Moved mStartupScript to World, so that it is executed for a New game
Merge branch 'master' of https://github.com/OpenMW/openmw into newgame