Merge pull request #352 from abersnaze/groovy-wrapper

Adding Func5-9 and N to the wrapper
[Gradle Release Plugin] - pre tag commit:  '0.12.2'.
[Gradle Release Plugin] - new version commit:  '0.12.3-SNAPSHOT'.
Version 0.12.1 and 0.12.2
Take Operator Error Handling

Unit test for https://github.com/Netflix/RxJava/issues/217
Merge pull request #353 from benjchristensen/take-unit-test

Take Operator Error Handling
implemented count operator (#32)
added sum operations
added test against long sum, too (#83)
implemented average operation (#25)
implemented skipWhile and skipWhileWithIndex (#80)
added interval methods to Observable, where they were still missing
removed unused imports
Added the two variants of the first operator.
Added FirstOrDefault operation
Added link urls to the msdn descriptions
Merge pull request #354 from jmhofer/count-sum-average

Count, Sum, Average implementations
Merge pull request #355 from jmhofer/skip-while

implemented skipWhile and skipWhileWithIndex (#80)
Merge pull request #356 from jmhofer/interval

Added interval methods to Observable, where they were still missing
add Observer wrapper to make subscribe(Observer[T]) work