Add Batch modules not currently covered by Boot

Before Boot 1.1.0 is released it will upgrade to Batch 3.0 and provide
dependency management for all of its modules [1]. In the meantime, the
Spring IO pom has been updated to override the value of the
spring-batch.version property and to add dependency management for the
modules not covered by Boot.

[1] spring-projects/spring-boot#800