Colour-related IDE improvements

* Now, special passages (Start, StoryAuthor, stylesheets, etc.) have
different-coloured title bars. I've tried to stick with earthy hues in
keeping with the colour scheme of the Twine icon, with redder hues used
for stylesheet and script passages.
* Now, connection lines representing <<display>> macros are drawn with a
bluer tint.
* Fixed the bug where importing .twee source code would discard all the
passage tags.
* Changed the unsaved changes dialog to give you the option of saving,
there and then.
* Fixed a small regex bug in the templates.
*
* Fixed the bug where importing .twee source code would discard all the
passage tags.
* Changed the '
* Fixed a small regex bug in the templates.
Fixed new passage positioning + other fixes

* Fixed the glitchy positioning of new passages - they are now placed
closer to the intended location.
* Passages tagged with 'Twine.' tags are now colour-coded gray.
* Altered the Greeking of zoomed-out passages to reflect the actual
passage text length.
* Doing a find-replace where the 'replace' string contains -, /, [, \, ]
or ^ no longer adds needless backslashes.
* Added syntax highlighting for raw inline HTML tags.
* Removed the 'Report a Bug' menu item.
* Incremented the version number.
* Updated the 'About' box credits.
Optimised "Import Source Code"

Added a new findSpaceQuickly method to PassageWidget that uses the old
and quick findSpace() behaviour, for use by StoryFrame's importSource().
Also, importSource() now caches the positions of each added passage, so
that findSpaceQuickly() has less work to do.
Various IDE improvements

* The shared engine code from all 3 formats has been put in a single
file, 'engine.js', in the targets folder. This is transcluded into each
template at build time.
* All formats: <<elseif>> is recognised as an alternative to <<else if>>
* Added 'Twine on GitHub' Help menu item.
* Added 'Import From Compiled HTML' option, letting the author recover
passages from built games.
* Deleted TW and TW2 and all references to them.
* The delete dialog now only asks once for deleting multiple passages,
and notifies how many passage have links to the deleted passages.
* The Story Statistics dialog no longer records stats from passages that
aren't part of the story (scripts, etc).
* Removed the unused toRss() function from tiddlywiki.py.
Minor StoryPanel and PassageWidget optimisations

* Fixed bug where importing passages with saved position data at a zoom
other than 100% wouldn't work.
* Changed the Redo shortcut on OS X to Cmd-Shift-Z instead of Cmd-Y.
* Caused some things (tiddler links, dragged widgets) to be cached to
slightly improve performance.
* Added Jonah's 'StartPassages' passage name to INFO_PASSAGE.
* Deleted PyRSS2Gen.
Quick bugfixes
Added StorySettings options for jQuery/Modernizr

* Fixed missing functions in Responsive.
* Responsive's jQuery and Modernizr includes are now separate files in
the targets folder that get inserted into any format at build time, if
the StorySettings 'jQuery' or 'Modernizr' are set to a value.
* StorySettings is now case-insensitive.
Fixed StorySettings error message

No longer gives a nonsensical error if a line in StorySettings isn't a
name:value pair (now just silently continues).
Reduced some overlap between Jonah and Sugarcane

Also:
* Added "visited()" as a function available to custom scripts (see
http://www.glorioustrainwrecks.com/node/5401).
* Normalised whitespace in engine.js.
OS X: moved icons into the app bundle
Merge pull request #81 from webbedspace/master

IDE improvements