Remove unnecessary quotes and curly braces.
Move configure options to local bash array for better handling.

Switch to correct license (GPL2).
Add all direct depends
Add all available sodeps in package() and the respective packages to makedepends.
Pin the required libao version by pkgver.
Add libao.so to provides.
Use a source tarball to build from instead of using unverified git sources.
Run autoreconf in prepare().
Update maintainer info.