Fix NPE from sendRequest() - no args (regression) Fixes #2530508

First sendRequest is fired immediately, async Fixes #2529182

setInterval was expecting the old signature to sendRequest.

Cleanup of submodule declarations for apidocs.

Removing scope property in support of Y.bind().

Set up polling with Y.later().

Initialize Pollable _intervals property in constructor and use augment() instead of build() since there are no Pollable ATTRs.

Use hash instead of array to track poll intervals.

Polling clearAllIntervals() bug fix and more tests.

Adding clearAllIntervals().

apidoc @submodule and moving _queue to xhr ds for now.

apidoc cleanup

DataSource [pollable] extension.

Changes per code review: Cache now Plugin not extension. DataSourceCache extends Cache and implements AOP on DataSource CE default functions. Must wrap default functions when publishing CE to support plugged subclasses. DS.Base -> DS. Local. Removed unnecessary namespace() calls.

No more DS.Local. Merged it into DS base class.

Move from util/ to src/