Deleting CodecBin1 and creating singletons.

Restricting the visibility of all codec constructors to private.
Adding singleton static getter methods to retrieve Codec instances.
Remove return type of ConcurrentCodable#encodeLock.

The return type was from a time when we were willing to sacrifice
data integrity to avoid deadlock. Deadlock is never acceptable.
When it is found the underlying bug must be corrected.
Merge branch 'master' into repair-api

Conflicts:
	src/main/java/com/addthis/codec/CodecJSON.java
Increment version number to 2.1.0-SNAPSHOT.
Merge pull request #2 from addthis/repair-api

Significant improvements to API