Respect settings and cli parameters

This change affects that spectacle respects both the settings and CLI parameters. The two bugs that get fixed, have the same issue. But they are activated on two different ways, one via CLI other via GUI. Copy image to clipboard and save to file were in one if (SpectacleCore.cpp L319). Which didn't allow to have the image both saved to the clipboard and as a file.

Fix for:

• Bug 425573: https://bugs.kde.org/show_bug.cgi?id=425573 "Spectacle does not save file in background mode"
• Bug 422148: https://bugs.kde.org/show_bug.cgi?id=422148 "Respects settings only when the spectacle window is opened"