Fixing strip markup functionality (when text too short to truncate)

Hi again Charlie,
While using Power Truncate recently I realised the strip markup functionality I stuck in worked fine when strings were being truncated, but when the supplied string is shorter than the requested truncate length, it wasn't being stripped out.

I have amended this in the EE2 & EE1 version (however am only able to test EE2). If it is useful you may want to bring it into your repo. If you do, don't forget to update Devotee.

(I wasn't sure what to do with the versioning or if I should have done anything so I changed it from V1.1 to V1.1.1).

Hope things are going well.
Kind Regards
- James