Username change handling

• username change events are received (even if happened after reconnect)

Add multiple users by username

Now we can add multiple users at once, the library defers the calls to prevent server errors.

Fix connection flags

• improved removing of multiple contacts

Username change handling

onUserNameChange method added to StatusWatcherCallbacks interface.

Fix connection to images DC

v0.2.48

Fixed online behavior

Update TG protocol to version 113

v0.2.40

Update tg protocol to version 113

v0.2.39

Fixed picture fetch from foreign DC.

0.2.38

Updated protocol to version 112.