Update codequality/checkstyle.xml

Removing as it appears to no longer be available in the latest version of checkstyle that comes with gradle 1.4
Upgrading to Gradle 1.4
Switching to bintray for dependencies (same as Maven Central)
Move gradle-release dependency to bintray
Use newer version of license-gradle-plugin that fixes skipExistingHeaders field
Add sonatype snapshot repository
Using latest features of release plugin
Upgrading release process
Matching wrapper to 1.5
Automatically aggregate and publish docs (java,groovy,scala)
Make uploadMavenCentral task, that encompasses other tasks
Handle unavailable sonatype properties
Verify before we can't take it back, use preferredVersion variable
Passing status to Artifactory builds
Fixing aggregateJavadoc
Adding mavenLocal() for local resolution
Merge remote-tracking branch 'build/multi-project' into update-gradle-wrapper-Aug2013

Conflicts:
	gradle/wrapper/gradle-wrapper.properties
Move githubProjectName earlier and set explicitly.
Update to Gradle 1.6 to match what was already in RxJava, but this version hasn't been tested thoroughly.
Merge pull request #341 from quidryan/update-gradle-wrapper-Aug2013

Update gradle wrapper to latest