CombineLatest fix
Moved onError, onCompleted and cancel.unsubscribed outside the lock
javadoc improvements:
* diagrams for skip(t), single(), take(t), skipLast(t)
* minor corrections, reformatting of javadoc comments
Merge remote-tracking branch 'origin/master' into docs
Adding diagrams, improving javadocs for sumFoo/averageFoo operators.
Merge remote-tracking branch 'origin/master' into docs
adding diagram to repeat() javadocs
Collect Operator
Merge pull request #701 from benjchristensen/collect

Collect Operator
Mark as Deprecated
Remove Extra Synchronization

The use of flatMap/mergeMap already synchronizes.
Standardize Naming of average/sum methods

See https://github.com/Netflix/RxJava/pull/698#issuecomment-31282416
Merge pull request #703 from benjchristensen/small-tweaks

Small Tweaks
Merge pull request #700 from Netflix/docs

various javadoc improvements
adjust javadocs for new sumFoo()/averageFoo() method names
Merge pull request #705 from Netflix/docs

adjust javadocs for new sumFoo()/averageFoo() method names
New contrib module: rxjava-async-util

Home for async utility functions with juc.Future, Actions, Functions etc that don’t need to be in rxjava-core.

As per discussions at:

- https://github.com/Netflix/RxJava/pull/646#issuecomment-31147005
- https://github.com/Netflix/RxJava/pull/645#issuecomment-31146492
- https://github.com/Netflix/RxJava/pull/622#issuecomment-31144128
Manual merge of https://github.com/akarnokd/RxJava/commit/eee312a6ac41582e4efe3daac3dfcd0385359d25

- To clean up the pull request I cherry picked the single commit with actual changes to avoid the merges that affected lots of other files.
- The original commit also included conflicting and unrelated changes to Observable and ObservableTests that I skippedManual merge of https://github.com/akarnokd/RxJava/commit/eee312a6ac41582e4efe3daac3dfcd0385359d25
Merge pull request #707 from benjchristensen/rxjava-async-util-module

Merge of rxjava-async-util
Merge branch 'CombineLatestFix' of github.com:akarnokd/RxJava into combine-latest