Merge pull request #373 from jmhofer/throttle-debounce-fix

a few warnings, javadoc, and one missing scheduler parameter
Merge pull request #374 from jmhofer/distinctUntilChanged

Implemented distinctUntilChanged operation
Merge branch 'distinct' of git://github.com/jmhofer/RxJava into distinct-merge

Conflicts:
	rxjava-core/src/main/java/rx/Observable.java
Merge pull request #377 from benjchristensen/distinct-merge

Distinct operator
UnitTests while working on EventStream use cases
Merge pull request #378 from benjchristensen/tests

UnitTests while working on EventStream use cases
[Gradle Release Plugin] - pre tag commit:  '0.13.1'.
[Gradle Release Plugin] - new version commit:  '0.13.2-SNAPSHOT'.
Version 0.13.1
added test with multiple subscribers
added missing mock
added another test against multiple staggered subscribers
wrapped subscription so that interval works for multiple subscribers and added a test for staggered subscriptions with publish/connect, too
initial introduction of an equality comparator into distinct implementation, still needs test
added test against comparator usage
added both new variants to observable
added comparator versions of distinct operation, too
added tests against multiple subscriptions, just to be on the safe side
implemented mapWithIndex
simplified error handling as this is already done on the outside