[TxMt] Soft Wrap defined in theme is annoying

[Jeroen van der Ham]

First of all, Allan confirmed that the softwrap feature is indeed broken,
this has nothing to do with the theme setting.

And softwrap would be defined in themes (although I don't think it
currently is) so that you can define it differently for plain text files,
where I would typically want it, for code, where I don't want it, etc.
So, I think it's a good idea, although it currently is not working very
well :(

Jeroen.