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
Improve testRecursiveScheduler2 determinism

Removed use of Thread.sleep and changed assertion to allow for the expected race condition between the counter loop and unsubscribe event to fix non-determinism issue reported in https://github.com/Netflix/RxJava/issues/329
Improve determinism of GroupBy.testUnsubscribe

Increased delta value from 2 to 10 to try and resolve issue reported in issue https://github.com/Netflix/RxJava/issues/329
Make Materialize.testMultipleSubscribes test deterministic

Refactored to use BlockingObservable instead of non-blocking subscribe and waiting on the underlying thread (it was only waiting on one of two threads running).
This should resolve one of the issues reported in http://github.com/Netflix/RxJava/issues/329
Merge pull request #332 from benjchristensen/issue-329-unit-tests

Issue 329: Fix non-deterministic unit tests