Add a demo.gif

Recorded using byzanz-record and this shell script:
http://askubuntu.com/a/201018
Don't need debuggable; 'ant debug' sets it anyway.
Remove 'span' from TableLayout

Seems it was this that was interfering with the TableLayout parameters and
squashing everything in.  Remove this span; it doesn't achieve much anyway.
Update development time

Completely ignores the hours spent searching for a good way to record
an animated gif on Linux.  Sigh.