Number key support

Rather than exiting with error.

Now xmenu detects if a menu has an icon, and if it doesn't have, the
menu will not have the gaps fgor icons, making the -i flag unecessary
to disable the padding.   The -i option is still necessary, however,
to speed up xmenu loading, since it disables imlib2 initialization
routines.

Reformat README to be nicer looking

little update to get people interested

Also changed license.

Redrawing an icon every time the cursor moves between items costs a lot
of time.  So now each icon is drawn once, and s copied when needed.

Changing config.cursx and config.cursy to config.posx and config.posy.
Adding the parseposition() function.

Widths and x positions no more depend on item->h.