Updated Hungarian translation
Shoot when the webcam capture button is pressed

This functionality existed is Cheese 2.32 (it was added in commit
de0114556cef148c396552d1c189b476ea0c8aab) but was lost in 3.0. Add it
back to fix bug 690961.
Update photo-take help page

Update language and add instructions for capturing photo using a
capture button on a webcam (bug 690961)
Updated Kazakh translation
Avoid deprecated GFile attribute syntax

Bump Vala requirement to 0.16.0.
Eliminate an instance-used-via-static warning
merge