add ability to add more rows to ticker

add ability to add more rows to ticker whilst it is running

can now call nt.newsTicker('add',"content of li"); 
to add items into the ticker whilst it is running
default min height - add buttons, make it accept data from a ajax command, set to scroll once through and then stop - add some keyboard shortcuts - allow it to work out the height it needs to move perfectly
set default min height as more intelligent
remove debugging