#161 Weight column tweaks

[Kevin Olbrich]

Many things get sorted by 'weight' in xoops, which is a
nice feature except for one problem. If you don't plan
ahead well enough, you quickly run out of room.

Say you have items with weights of 1 and 2. If you
generate a new one that you want between them, you
have to reassign all the subsequent ones to keep the
order right.

Why not just make the 'weight' columns a floating point
number? That way you could enter something like 1.5
to go between 1 and 2.