SCHEMA-190. Removed KijiDataBuffer.

Signed-off-by: Milo <milo@wibidata.com>
SCHEMA-151. Improve version number reporting

Added ProtocolVersion to describe a versioned protocol or format.
VersionInfo returns ProtocolVersions not strings, where appropriate.
KijiTableLayout tests a layout's specified protocol vs. the range
    of protocol versions supported by the client.
Update all tools / tests to use the new version API.

Signed-off-by: Milo <milo@wibidata.com>
SCHEMA-150. Update CLI tools with support for composite keys.

 - Short fix to pretty-print entity IDs in "kiji ls".
 - InstanceBuilder supports composite entity IDs.
 - InstanceBuilder supports populating existing tables.
 - More unit-tests for kiji ls.
 - Reorganize kiji delete flags (--timestamp=latest|all|<ts>|upto:<ts>).
 - Split IntegrationTestKijiAdminTools into more focused, specific unit tests.

Signed-off-by: Milo <milo@wibidata.com>