users should keep in mind that this is not the fort knox of password storage, and someone who copies your config file could rainbow table a short password stored with this hash very easily. at some point in the future, if someone has the interest and time, perhaps this can be improved
fix T1627
after this commit, the new-but-invisible module "lokker" (or other custom loaded module) is in charge of creating all graphics for the lock screen, and it will be added to the user's config. failure to load a lockscreen module will just result in a black screen
desklock subsystem now handles all the pre/post lock stuff while the modules themselves are responsible for creating visuals and calling auth functions to determine whether to unlock the screen