Coding style tweak
Add support for action widgets

This is part of the groundwork for fixing #336
Add a new journal page toolbar button

Spot the easter egg with the toolbar button…

Fixes #336
Make new journal title and tags be configurable
Update "Introduction to Filters" docs
Simplify new journal button
Add "new here" button

This is a basic “new here” tiddler toolbar button that just creates a
new tiddler tagged with the title of the current tiddler.

@pmario is there anything else required?
Merge remote-tracking branch 'upstream/master'