#i124935# fix expanded/condensed text breaking in the CoreText engine

the concept of an extra-width per code-unit was obsolete at least since apps
supported unicode with its different normalization forms, diacritical marks,
surrogate-pairs, non-printing characters such as ZWJ/ZWNJ/RLM, etc. so of
course modern engines like CoreText don't aid this typographical crime. Text
expansion/compression to a specified width percentage of a plain text layout
would be a much better alternative to the per-code-unit expansion which should
be removed if was not backward compatibility of text layouts.

The fix here extends the CTLayout::GetTextBreak() method to handle the obsolete
semantic of per code-unit extra-widths by successively approximating the number
of involved code-units.

Merged from AOO's trunk revision 1596218


git-svn-id: https://svn.apache.org/repos/asf/openoffice/branches/AOO410@1602369 13f79535-47bb-0310-9956-ffa450edef68