CDK-537: Check for empty views and return 0 splits.

This updates the FS implementation's InputFormat to check the incoming
view using isEmpty to fix the setInputPaths bug. FileInputFormat assumes
that setInputPaths is called with at least one path. MR tests have been
added for both FS and HBase.
Merge pull request #144 from rdblue/CDK-537-fix-mr-empty-views

CDK-537: Check for empty views and return 0 splits.
CDK-540: Handle other GenericRecord implementations in FileSystemDatasetReader

 * FileSystemDatasetReader now handles other implementations of GenericRecord
 * HBase won't handle them, but that is not a regression and will be fixed in
CDK-541.
 * Added a test for CSVFileReader.
Merge pull request #147 from joey/fix_type_for_read_generic

CDK-540: Handle other GenericRecord implementations in FileSystemDatasetReader
CDK-538: Added unit tests for DataModelUtil.
Merge pull request #146 from joey/datamodelutil_tests

CDK-538: Added unit tests for DataModelUtil.
Javadoc fixes.
Update release notes for 0.15.0 release.
[maven-release-plugin] prepare release release-0.15.0
[maven-release-plugin] prepare for next development iteration
Update jdiff files.
CDK-542: Fixed Avro 1.7.4 incomaptabilities in DataModelUtil
Merge pull request #148 from joey/avro_1_7_4_compat

CDK-542: Fixed Avro 1.7.4 incomaptabilities in DataModelUtil
[maven-release-plugin] prepare release release-0.15.0
[maven-release-plugin] prepare for next development iteration
CDK-519: Updated travis configuration to Oracle JDK7.
Merge pull request #149 from joey/cdk-519-travis-to-jdk7

CDK-519: Updated travis configuration to Oracle JDK7.
Add Range#toString and Range.fromString methods.
Add Predicates toString and fromString methods.

Range and In are handled directly, other predicates will use
RegisteredPredicate to register a factory for a name. Registered
predicates are converted to "name(<...>)" strings, where name is a
registered name and the inner part is produced by toString. Exists is
now a RegisteredPredicate.
Move predicate classes into new spi.predicates package.