It should be called "align", but the name is already taken
It doesn't use awful.placement because it would break the dependency
graph.
Some cases previously required 2 wibox.layout.align layouts,
one for each axis. This is massively overkill to simply place
a widget at the center of a larger area.
It does not provide much value. The version number is already known to
ldoc globally in the "description" variable.
Signed-off-by: Uli Schlachter <psychon@znc.in>