Left: auto update, privacy and security, local storage box +
some minor things, like design fixes, codes like loadlang and
clearing of the local storage (box) and temp download folder.
Now the background of boxes is separated to another widget.
This will allow to use a special layer widget (like settings)
together with the usual layers-boxes upon it, moving the special
widget behind the dark background when a usual layer-box is shown.
All errors that lead to MTP request resending by default
error handler now can be handled differently. For example
inline bot requests are not being resent on 5XX error codes.
+ extensive use of auto keyword in MTP types handling.
