Optimized battery consumption, fixed blurry photos on some devices, added option to auto download media only via WiFi, changed way of contacts changes monitoring

https://github.com/DrKLO/Telegram/pull/422
https://github.com/rubenlagus/Telegram/commit/d96ce3c140bd49c5c8c63cea2b
c9afad8a16b8bb
Merge remote-tracking branch 'remotes/upstream/dev' into dev

Conflicts:
	TMessagesProj/src/main/res/values-it/strings.xml