[css3-multicol] page-break-inside and columns

There appears to be one remaining issue before the WG is comfortable
sending css3-multicol to Last Call. The current editor's draft:

  http://dev.w3.org/csswg/css3-multicol/#column-breaks

states that he 'page-break-inside' property specifies the behavior of
natural column breaks inside elements. That is, if you set:

  p { page-break-inside: avoid }

the formatter will try to avoid both page breaks and column breaks
inside p elements.

In most cases, this is what the author wants, I believe. However,
there may be cases where the author really cares about avoiding page
breaks but doesn't care about column breaks. 

I propose to address this by having two keywords on the
'page-break-inside' property:

  'avoid' -- avoids page breaks
  'avoid-all' -- avoids page breaks and column breaks

One argument against 'avoid-all' is that it doesn't avoid line breaks.
However, I can't think of a better name. 

It should also be noted that using the page-* propoerties to set
preferences on columns is not ideal. However, introducing three new
properties to describe column behavior seems excessive. 

Opinions welcome.

-h&kon
              Håkon Wium Lie                          CTO °þe®ª
howcome@opera.com                  http://people.opera.com/howcome