[CSS21] new value display property proposal: block-inline

Sorry for repost, the subject needed to be changed and text to be modified

Hello world, -first time for me here-

I often use inline-block, a useful property, but to align block
without floating elements, inline-block is unfortunately not a good
way, the white-space between 2 tags will makes the size wrong (imagine
2 blocks with a 50% width + the space, it goes to next line).

So block-inline will have the same effect like inline-block but
without the white-space.

/toni