Auto xib update by Xcode
Documents fill screen size on default
Change new document behaviour

Yosemite doesn't save frames for unsaved documents, so the original
behaviour (all unsaved documents use a common name) doesn't work
anymore. Fallback to a more trivial one that always maximises.
Add checkbox for auto-increment toggle

Fix #169 (regression introduced by merge commit c153040)
Use latest SDK to silence warning