kiji-schema: SCHEMA-675. Adds support for configuration of Kiji column name translation.

This can be done via the ColumnNameTranslator field of KijiTableLayouts.

Signed-off-by: Christophe Taton <taton@wibidata.com>
commit: https://github.com/kijiproject/kiji-schema/commit/5cd385ba84fc530f551151321117c0c4114033a3