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
Make DummyObservable visible to clojureTest classpath.

RxJava issue #327. Moved DummyObservable into main so that it's
compiled and available when the clojureTest task executes. Perhaps
someone with stronger Gradle skills can figure out how to put this Java
class in src/test and get things to work out. Correctly. For the time
being, several clean/build cycles worked fine for me.
Merge pull request #330 from daveray/issue-327-clojure-build

Make DummyObservable visible to clojureTest classpath.
RxJavaPlugin Unit Tests

Attempt to fix non-determinism https://github.com/Netflix/RxJava/issues/329
Made unit tests work on private instances in each test rather than against static global.
Improve testNoBufferingOrBlockingOfSequence determinism

Removed use of Thread.sleep to fix non-determinism issue reported in https://github.com/Netflix/RxJava/issues/329