[PATCH] tweak rounding on weston-terminal resize

[Jason Woofenden]

Thank you Pekka Paalanen and Kristian Høgsberg for your review and
feedback.

I can't believe I forgot to compile and test again before sending
in that patch.

I played with it a bit before refactoring, and I like the way it
looked/responded while resizing. But now (thanks to Kristian) that
I think more about other cases, I can see that it would be bad for
the client to pick a size larger than that requested.

-- 
Jason