Fix the iOS coloured text problem

The eventual text colour is not known yet when LayoutText() is
called. So we need to re-do the layout and justification in DrawText()
in case we have a text colour.

For some reason this is needed only on iOS. On OS X, the original code
manages to display coloured text correctly. But then, on iOS a virtual
device is used, and who knows what other strange things going on. Some
of the scary warnings printed make you a tad unsure everything is
working correcly... (Like "SdrPageView::DrawLayer: Creating temporary
SdrPageWindow (ObjectContact), this should never be needed (!)")

Change-Id: Ide99c163dea0f758a373c8dab9c54681ff57f624