Updated example and code, added transitions, and moved sections
LRDOCS-493 Added section on Asset Publisher's two subscription options: RSS and email; discussused the following two configurable properties: asset.publisher.dynamic.subscription.limit=20 and asset.publisher.check.interval=24
LRDOCS-464 Edit and modify some formatting in hooks.
Merge pull request #509 from jrao/LRDOCS-493

http://issues.liferay.com/browse/LRDOCS-493
Merge pull request #512 from jhinkey/LRDOCS-464

LRDOCS-464 DevGuide Hooks addressed comments
Wordsmithing.