Add QBS build files.
Add native toolbar to preferences window.
Update QtMacExtras to fix a compile issue.
Don't moc QtMacExtras files on non-Mac platforms.
Update submodules.
Update submodules.
Whitespace fixes
Ignore third-party code in stylechecker.
Update core submodule
Update core submodule
Remove dead testing code from browser.
Fix qbs build.
Update submodules.
Fix that will be needed for Qt 5 build.
Update core
Remove some dead code remnants.
Use forward declaration where possible.
Remove dead code.
Fix bug in file open logic.

Previously the app would always open a file called "YES" when run from
Xcode.
Update submodules (plus a one-line compile fixed related to the update).