UILineBreakMode*Truncation modes (leading/trailing "…") and multiline

Word Wrapping and Truncation is not well managed.

Today the OHAttributed does not support both multiline (numberOfLines>1) and "Truncation" lineBreakMode alltogether : if you choose one of the UILineBreakMode*Truncation mode, only the first line will be displayed.

It is probably easy to add the UILineBreakModeTailTruncation mode support by using the VisibleStringRange information (I just don't have time to add this right now)