xdotool: new package

xdotool is a command-line X11 automation tool.

http://www.semicomplete.com/projects/xdotool



[Thomas:
 - fix <pkg>_LICENSE, as noticed by Baruch
 - use $(TARGET_MAKE_ENV).]

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>