SAV1 0.9.1

This release brings several "build config" improvements:

• Builds are now smaller, since the debug symbol table is stripped by default
• Now possible to build SAV1 with dependencies as meson subprojects
• New mac CI
• Warning fixes

There are also some changes to the Sav1AudioFrame struct, see 01a294d.

This release provides prebuilt binaries for Windows and Mac (x86_64) only.

• The mac build has a DEPLOYMENT_TARGET of 10.9, comes with dependencies built into libsav1.dylib
• The windows build has dependencies bundled as shared libraries.

SAV1 Version 0.9.0

This is a mostly-functional release of SAV1 for the purposes of the Oregon State University capstone program.