setup key combo from within shutter to take screenshots (similar to how mac's do screencaps)

[fcortesjp]

Description of requested feature:

would be nice to have screen cap operation initiated by key combo with shutter right after installation (like mac has it built in)

Reasons for adding feature:

I come from mac and they use key combos that can start a screencap operation, it's nice and quick. at the moment you need to setup that combo in linux to start the screen capture operation in shutter plus you have hit enter after the screen cap has been take so it can be available in the clipboad.

Extra information, such as Shutter version, operating system and ideas for how to implement:

0.99.2 on linux mint

[Photon89]

The problem is that the services that are responsible for catching key combos are desktop specific. Also, I think, it would be quite invasive if an app registered such a key combo (what if several apps did it and used the same key combo?).

Regarding hitting the enter key to confirm the screenshot in selection mode, an option to disable it is implemented with a recent PR, here's the corresponding issue: #590