* first pass at fixing bug 7878, needs testing
* clarify default behaviour in comment
* fix property typo, tested and works as intended
* remove debugger
A first pass at fixing #2973 - comments are welcome. If everybody is
happy, the next step is to deprecate the existing
rendertiddler(s)/savetiddler(s) commands and replace them in all
examples and tiddlywiki.info files with the new equivalents.