Adding reply and link preview to python API.

Merge branch 'fix_command_typing_with_status' of https://github.com/luckydonald/tg into luckydonald-fix_command_typing_with_status

[commands] Fix for ```send_video``` failing without a caption string given.

[json] Add user online status event

fix include orders because python defines _GNU_SOURCE unconditionally and it can collide with other libs

That's what you get when using regexes...