Closes #70, closes #52

This PR attempts to demonstrate some of the features of Elide

• Integration with Spring Security (when app.security.enabled=true)
• Using obfuscated ids
• Using alternate ids
• Using a custom data store to perform operations such as sending an email
• Using a custom data store to use Spring Data for queries
• Using cursor pagination

I confirm that this contribution is made under the terms of the license found in the root directory of this repository's source tree and that I have the authority necessary to make this contribution on behalf of its copyright owner.