EXP-20. Adds RunSpec.

Reviewed by: kiyan
EXP-55. Allow KijiExpress to build against CDH4.1.2 and CDH4.2.1

This commit modifies the pom to include a profile that can build against
CDH4.1.2 (the default) and against CDH4.2.1. The profile that can build
against CDH4.2.1 also builds against compatible versions of kiji-schema
and kiji-mapreduce. This commit also includes changes to disable schema
validation in KijiSchema 1.1.0, as currently the validation is too strict
to be compatible with KijiExpress.

Reviewed by: robertchu
EXP-42. Adds a ModelProducer class for running Extract and Score.

Reviewed by: kiyan
EXP-56. Renames RunSpec and ModelSpec.

RunSpec is now ModelEnvironment.
ModelSpec is now ModelDefinition.

Reviewed by: kiyan
EXP-57. Removed references to model pipelines.

Reviewed by: kiyan
EXP-60. Adds ExtractScoreJobBuilder.

Reviewed by: kiyan
EXP-60. Adds back missing comma to fix build.
EXP-58. Allow settings on ModelDefinition to be modified.

This commit modified ModelDefinition to allow users to override
settings on a model definition.

Reviewed by: robertchu
Adds pack/unpack methods to KijiPipe for AvroRecords.

Reviewed by: kiyan
EXP-59. Allow settings on ModelEnvironment to be modified.

This commit modified ModelEnvironment to allow users to override
settings on a model environment.

Reviewed by: robertchu
EXP-61. Adds Tool for running extract-score jobs in batch.

Reviewed by: Kiyan Ahmadizadeh and Robert Chu
EXP-66. Removes the need to cast when using KVStores.

Reviewed by: Robert Chu
Update to latest non-snapshot versions for release.
[maven-release-plugin] prepare release kiji-express-0.4.0
[maven-release-plugin] prepare for next development iteration
EXP-63. Adds support for kvstores to ExtractScoreProducer.

Reviewed by: kiyan
EXP-70. Implements a KijiJob with implicit conversions for KijiPipe.

Reviewed by: robertchu
EXP-54. Adds precanned selection extractors.

Reviewed by: kiyan
Modify pom.xml to use Kiji root pom 1.1.0.

Reviewed by: robertchu