AAD Codec Version.18

code refactoring for table.

AAD Codec Version.17

replace header decode & set API to set-only API.

AAD Codec Version.16

add format/codec version member to header.

AAD Codec Version.15

add header decode and set api.

AAD Codec Version.14

fix asymmetry table (for 4bit) bug.

AAD Codec Version.13

This is the first release of AAD.