Use SingletonSerializer for Unit
Merge pull request #130 from twitter/unit-ser

Use SingletonSerializer for Unit
Use references in Externalizer
Merge pull request #131 from twitter/useRefs

Use references in Externalizer
handling of java-only
add changes
Merge branch 'release/0.3.2' into develop
add unit test for serde trait with reference of self
reproduce issue #134
DO NOT ignore synthetic fields always
Merge pull request #135 from tsdeng/add_unit_test_for_trait_using_self

add unit test for serde trait with reference of self
Merge remote-tracking branch 'origin/develop' into feature/fix-NPE

Conflicts:
	chill-scala/src/main/scala/com/twitter/chill/KryoBase.scala