- Modified the build definition to fork the JVM when running tests.
- Modified the build definition for the `io` sub-project to keep up with the latest stable release of Avro (1.7.4 => 1.7.5).
- Added an overloaded definition for AvroTypeIO.write to allow subclasses to share BinaryEncoder instances.
- Updated write methods in collection types (AvroArrayIO, AvroMapIO, AvroSetIO) to use the more low-level encoder API.
- Updated the union resolution logic in AvroBareUnionIO and AvroClassUnionIO for compatibility with aliased types (Java primitives, etc)