Get rid of the repudiator.

fixes #1068

this will lower the number of cycles involved in processing a response
by a fair few, but in terms of visible change for individual users
impact is probably imperceptible.

the issue will remain in place with a link to the commit that removes
the code, in case we need to resurrect it (as a plugin or otherwise)
Merge branch 'master' of github.com:TiddlySpace/tiddlyspace