Add mouse support
Cleanup command parsing logic
Increase read buffer

We're getting a lot more text now, what with the mouse click commands.
This took longer to debug than it should have.
Account for screen offset when calculating clickable area positions

Works with XINERAMA now. Tested with:
echo '\ableft1\ac echo left1 \ae\c\abcenter1\ac echo center1 \ae\r\abright1\ac echo right1 \ae\sn\ableft2\ac echo left2 \ae\c\abcenter2\ac echo center2 \ae\r\abright2\ac echo right2 \ae' | ./bar -p
Merge branch 'for-lemonboy' of https://github.com/u-ra/bar<
Fix conflict

Conflicts:
	bar.c