Patch release for 1.13 that fixes incorrect behavior.

• GL: Black screen when antialiasing forced on in NVIDIA driver settings — Doomsday will use NVIDIA CSAA if available
• UI: Transition sometimes showed up as all-white when leaving a map
• Heretic: Transition from intermission to the next map
• OS X: Build failure in Snow Leopard

• Roadmap: 1.13.2
• 1.13.1 release notes
• 1.13 release notes