Please add screenshot hotkey feature

[adahbingee]

• [*] I have checked that a similar feature request does not already exist.

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like

hotkey for screenshoot e.g CTRL+SHIFT+s

best quality lossless screenshot, and save at directory by incremental naming e.g. %04d.png

adb shell screencap -p /sdcard/screen.png
adb  pull /sdcard/screen.png ./

[teunissenstefan]

Using the "screencap" method, apps can detect if a screenshot has been taken. If this feature gets implemented I hope that a method will be used that apps cannot detect. Like exporting a frame of the video stream for example.

[rom1v]

Duplicate of #684.