#i125020# fix the repainting problem for update rectangles with CoreText

by doing the calculation before CTLineDraw() updates the text position.
Requesting the update early is possible because that update region is
not used until AquaSalInstance::Yield().

The fix also accounts for worst-case rounding effects when the processing
the repaint rectangles.

Merged from AOO's trunk revisions 1599169, 1599173 and 1599174


git-svn-id: https://svn.apache.org/repos/asf/openoffice/branches/AOO410@1602370 13f79535-47bb-0310-9956-ffa450edef68