Added some built-in blend States, Multiply an Multiplyx2
Remove dependency on Linq in KeyboardState.cs
Respond to invalid touches properly: e.g.: release them.

Code was sticking input on task switching.
exposed (non-standard) access to usually hidden methods and properties in Song.cs.

This is a hack
Hack: set cull mode on BasicEffect apply.

Workaround for state leak problem.
Added some built-in blend States, Multiply and Multiplyx2, part2 (the effective part)
Debug performance counter improvements
Change sound exceptions into console writes..

If a sound doesn't play, we don't want to bring down the app.
Hack: Non-standard XNA: expose "GetFilename" of ContentManager
Unknown fix to Sound.cs.

On Sound.Play, instead of resetting current time in a thread pool, we simply call Play();

Consider why a thread pool queue was used there in the first place.
Compat change due to Xamarin upgrade
Bugfix: Make sure not to break parsing strings in non-english locales.
Added debug diagnostics for tracking resources.
#define RESOURCE_TRACKERS to use.

Tells you when was the last time a given resource was used. Helpful for pruning loaded but unused assets.
Fixup CR (mac line endings) to unix line endings
Added debug diagnostics for tracking resource usage.
Part 2
Hack: Shenanigans to get framerate smooth 30fps
Insignificant casing changes in the project file
Improve SoundEffect system to use OpenAL (missing project changes to add files)
Crazy performance improvement to SpriteBatcher.
Some sorting functionality was disabled in this change.
Main change is moving SpriteBatchItem from a class to a Struct
Cullmode improvements (possibly partial change, check in past changes)