REST-69. Modularizes KijiREST in preparation for custom endpoints.

Refactors standard resources (version, instance, table, rows, etc.) into StandardKijiRestPlugin.
All resources, exception handlers, and serializers must be registered in the
KijiRestPlugin#install(Environment) method.

issue: https://jira.kiji.org/browse/REST-69
review: https://review.kiji.org/r/1441