Adds working with Avro section to KijiMR userguide.

Signed-off-by: Milo <milo@wibidata.com>
Edits to Setup and PlayCount pages
reviewed by: Lee

Signed-off-by: Daisy Zhou <daisy@wibidata.com>
Revises bulk importer sections. Minor fixes.

- Revises bulk import section.
- Moves working with avro to new home.
- Updates order of testing section of KijiMR UG to 10.

Signed-off-by: Milo <milo@wibidata.com>
Fixed phonebook tutorial links.
Further details on the testing framework

Signed-off-by: Robert Chu <robert@wibidata.com>
KijiMR UserGuide - Reducers classes overview