D-Bus protocol update

Updated to use the latest D-Bus protocol as of Way Cooler 0.7

Now grabs focused output

The program now gets the focused output's frame buffer, instead of just the oldest created one.

Incompatibility

This is a minor version bump, because this version of wc-grab is not supported for any version of Way Cooler that is before v0.6.1.

v0.1.0

Initial release of wc-grab. Can take pictures, and output it to a specific file.