kiji-rest: 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
commit: https://github.com/kijiproject/kiji-rest/commit/44d6b81185ed82a182b2a6003797b6816a939d39
kiji-express: EXP-322. Touch up scaladocs of ColumnOutputSpec and its subclasses.

issue: https://jira.kiji.org/browse/EXP-322
review: https://review.kiji.org/r/1442
commit: https://github.com/kijiproject/kiji-express/commit/8e1547dd2287ff8f654768433791521ab1b05dd7
kiji-rest: REST-69. Renames plugins dir to services to be compatible with ServiceLoader.

reviewer: lsheng
commit: https://github.com/kijiproject/kiji-rest/commit/175e45f6c7f798a655f87451a427c9f8dc81b0b6
kiji-rest: REST-80. Correctly use KIJI_REST_CONF_DIR for location of conf directory.

issue: https://jira.kiji.org/browse/REST-80
review: https://review.kiji.org/r/1443
commit: https://github.com/kijiproject/kiji-rest/commit/8f59c9e3bb425c65701a3efbd40ca3743e0ba3bb
kiji-mapreduce: KIJIMR-163. I want a mapper that reads from a table and writes to a table

 - KijiPivoter SPI, job builder, CLI tool, unit-test.

issue: https://jira.kiji.org/browse/KIJIMR-163
review: https://review.kiji.org/r/1435
commit: https://github.com/kijiproject/kiji-mapreduce/commit/2f6f91372cb3824cce7acf87349425b2891c2ee7
kiji-express: EXP-326. Seq[FlowCell]s from paged columns have unexpected behaviour

issue: https://jira.kiji.org/browse/EXP-326
review: https://review.kiji.org/r/1433
commit: https://github.com/kijiproject/kiji-express/commit/8b0dd88c755bb24566544a08ea3968a194b3ebae
kiji-express: Add a relative project reference for the base project files

Signed-off-by: Caitlin Johnson <caitlin@wibidata.com>
commit: https://github.com/kijiproject/kiji-express/commit/23e417c0c2d79b40eb03d37eaf3f86282fc62c8a