Full multimonitor support! Settings file!

This release marks the milestone of finally getting multimonitor support for the screenshotting functions. I haven't tested on many configurations, but it seems to work fine.

Currently, the default monitor setting is kept in the rectangle coordinates format, so displays will appear as (x1, y1, x2, y2), where (x1,y1) is the top left, and (x2,y2) is the bottom right. For your primary monitor, x1 and y1 will be zero. Negative values indicate the screen is to the right of your primary.

Also, logfiles now give device type, which is hugely useful.