Basic Safari, Mozilla support, perfomance improvements, bugfixes

* Added data:image/jpeg;base64, mode for small images on browsers,
which dont support LocalFileSystem. Please use Chrome for full
experience
* Speed-up chat modal window, by making getFullChat request asynchronous
* Added basic error handling for photo/video modal windows
* Improved dateOrTime filter perfomance by caching its values
* Added sentMessages cleanup
* Guest DCs networkers now dont perform http_wait if no sentMessages
pending
* Added favicon blinking on new message