Warning for hidden text in target in Trados-Tagged RTF

[Former user]

Original [issue 152](https://code.google.com/p/okapi/issues/detail?id=152) created by @ysavourel on 2010-12-10T17:38:08.000Z:

It would be useful to get a warning if a span of hidden text is detected when processing the data inside the target part of a RTF segment, before the end-of-segment marker.

[Former user]

Comment [1.](https://code.google.com/p/okapi/issues/detail?id=152#c1) originally posted by @ysavourel on 2010-12-10T20:14:38.000Z:

Implemented. Will be in M10.