Improve variable handling when rebuilding build.ninja

Variables which are not referencing other variables are no longer provided with their literal value. Variables which do reference other variables have the reference escaped, so that ninja won’t expand the reference when rebuilding build.ninja.

There is still some redundancy in that APP_VERSION has the major + tag part stated both at the top and as a command line argument, haven’t yet figured out how to best deal with this.
Make bundles in bundle preferences table sortable
Don’t log unchanged sources as failures
Extended OakTextView API

Added `scopeAsString` method to retrieve current scope as NSString
Use NSHost to obtain computer’s name
Use NSNumberFormatter class method

Once we drop 10.7 support we can avoid NSNumberFormatter entirely by using ‘localizedStringWithFormat:’ with ‘%lu’.
Use localizedStandardCompare:

This is instead of our custom displayNameCompare: which has now been removed.
Use new focus ring API (10.7)
Remove instance data from OakTextView.h
Harmonize a few properties

This is just implementation detail.
Disable font smoothing for dark themes

If you wish to always have font smoothing enabled you can run:

    defaults write com.macromates.TextMate.preview fontSmoothing 1

Setting the value to 0 causes it to always be disabled and deleting the key (or setting it to 2) has it disabled only for dark themes.
Restore field editor’s value after reloading file browser

If user was creating a new file or folder and immediately started to type in the field editor, his changes were lost during reload (which would likely happen when updating SCM badge for the newly created item).
Add completion callback to installBundle:
Close bundle install sheet on error

Previously incase of error the sheet would keep showing effectively locking up the document window.

This is related to issue #85 although the reason why installing bundles fails for some users is still unanswered.
Checkin release notes
Only disable font smoothing on high-DPI displays

The fontSmoothing defaults key can now be set to:

 0: Always disabled
 1: Always enabled
 2: Disabled for dark themes
 3: Disabled for dark themes on high-DPI displays (default)

/cc issue #958.
Use blocks for document save callback
Fix refresh/undo for commands causing document saving

Since saving is asynchronous the scoped refresh/undo helper would do “cleanup” before the command ran and potentially made document changes.

Commands executed at a lower level (i.e. by editor_t via macros) presently still has this issue. This should be fixed when macros are refactored (this isn’t the only issue related to macros).

Closes #450.
Checkin release notes
Use trackSwipeEventWithOptions:… for swipe gestures