Require confirmation before abandoning edits

Fixes #544
Release note updates
Allow spaces in property names in text references
Make tiddler width fluid when sidebar hidden
Fix Cecily tiddler width for when sidebar hidden
Add chinese translations of confirmation for cancelling edits
Docs typo
Adjust Cecily tiddler width
Merge pull request #552 from BramChen/master

Add chinese translations of confirmation for cancelling edits
Merge remote-tracking branch 'upstream/master'