Make all second level headings article
Use NSBox to draw gutter divider

There’s a few subtle advantages of going with a view, mostly theoretical (about minimizing refresh rectangles) but switching to constrained based layout should provide minor code simplifications, since our ancestor view won’t have to deal with the gutter divider rectangle.
Rename property: layout → layers

This is to avoid a clash with the layout method introduced in 10.7 (and used during auto layout).
Fix typo
Include SCM info in default window title

Ideally I also wanted to include project directory, but since the user’s properties are read after the default ones, and those contain the setup of projectDirectory, this isn’t possible with the current semantics.
Update project properties

Mainly just rely on default SCM window title.
Auto-layout: Implement intrinsicContentSize
Auto-layout: Update file browser and HTML output
Auto-layout: Update incremental search (xib)
Gracefully handle missing gutter view delegate
Auto-layout: Update OakDocumentView

The gutter will invalidate its intrinsic size when its width changes which will cause the Cocoa layout engine to update the layout, so no more explicit code to deal with adjusting the gutter’s width.

Likewise, the height of the gutter (not the gutter scroll view) has been setup to match the height of the text view (again, not the containing scroll view). This avoids observing the text view frame and manually updating gutter height to match it.
Ensure builddir doesn’t contain removed files

If e.g. we rename “image.tiff” → “image.png” then the build files are correctly updated to copy “image.png” to the build directory, but until this commit, the old tiff image would stay in the build directory until manually removing it / cleaning the build directory.
Auto-layout: Encapsulate tab bar expansion

With auto-layout the tab bar view can simply invalidate its intrinsic size when it should expand/collapse. This is also done if the global user setting for disabling tab bar collapsing is changed.
Remove resize buttons

Going forward we only allow resizing views by grabbing the dividers.
Remove unnecessary include
Constrain size of splits in main window

The main window has now moved fully to constraint based layout which makes it a lot easier to tweak the layout and fixes issue #145.

Presently the option to have HTML output on the right is not supported. It will likely be back with a few other options that have been requested.

The width of file browser and height of HTML output view is always read from defaults rather than restored from previous session. Effectively this results in the same behavior except when there are multiple windows with different sizing of these splits. Unsure if per-window sizes should be brought back.
Remove legacy code
Remove Chinese translation

It’s not feasible to maintain the old-style xib translations while we work on the UI. We’ll soon move fully to constraint-based layout which should allow translations to be purely string-based.
Fix format string in xib

Was using the (undefined) ‘Extension’ variable instead of ‘X’.
Add glob test: ‘*.ext’ doesn’t match ‘.ext’

I wasn’t sure if this was really desired, but it mimics bash.