Update from Gradle 1.10 to 2.0

* This required only one change to the source, which was a
  suppression of a CodeNarc rule that is now being triggered in
  DataSources
* Did not update to Gradle 2.1 (the current version) because it
  gives a build error
Adapt to the updated Groovy version in the new Gradle

The new Gradle version pulls in a newer version of Groovy, which
broke some code.
Extract duplice dependency version numbers into versions.gradle

Many libraries that neon depends on have more than one component,
and the components should always use the same version. To help keep
everything consistent, put the version numbers of all such libraries
in gradle/versions.gradle
Move Hive libraries into sparkSQLDependencies.gradle

The Hive libraries are only used by buildSrc and the Spark stuff, so
move them into sparkSQLDependencies.gradle and have
buildSrc/build.gradle include that file.
Upgrade to Gradle 2.1

GruntTask inherits from gradle's ExecTask, which changed slightly.
Fixing GruntTask to run the ExecTask.exec() method properly solved
the resulting build problem.
Simplify Hive dependencies

The Hive dependencies were more complicated when Neon used Shark, but
they can now be simplified. They are only needed at runtime, because
they are dynamically loaded for the JDBC driver.
Minor cleanup of Hadoop dependencies

The Hadoop common is only needed at runtime (by Hive), and the HDFS
transitive dependencies no longer conflict with other parts of the
build.
Remove stale repositories from the gradle files

Shark required local libraries that are now available from Maven
Central, and for a brief period Spark did as well.
Remove unneeded codehaus.org repository

The corresponding libraries seem to be available from Maven Central
Apply versions.gradle in the root project

Sub-projects inherit properties from the root project, and the
versions are meant to be global properties.
Move all library dependency versions into versions.gradle
The subprojects do not need gradle wrappers
Remove dead code from performanceTest.gradle
Move the grunt watch task to js.gradle

All of the other grunt tasks are in js.gradle, but the 'watch' task
was in neon-server/build.gradle, which is the only file that includes
js.gradle.
docsUtils.gradle is for utilities needed by docs tasks

The previous name of the file, docs.gradle, indicated that it is
where everything related to generating documentation should go, when
it is really a place for shared utilities required by various docs
tasks.
Clarify where the antlr-runtime 3.5 dependency comes from
Use task input/output to determine grunt dependency

The installGruntDeps task needs package.json to be up-to-date, so
state that more explicitly in the task definition.
Clean up the output of 'gradle tasks'

There were a lot of intermediate tasks that showed up in 'gradle tasks'
because they were assigned to a group. For those tasks, the group
was removed so that they would be automatically hidden. Unfortunately,
tasks that are pulled in via finalizedBy are not automatically
hidden.
Skip Spark SQL integration tests if no spark host is specified
Skip MongoDB integration tests if no mongo host is specified