waffle-shiro: add new waffle-shiro component with basic realm implementation

This currently only supports username/password authentication.  Support for "negotiate"
will require a custom authentication token, a shiro security filter, and minor
enhancements to the realm.

Based on work discussed in the following ticket:
https://issues.apache.org/jira/browse/SHIRO-385
waffle-shiro: add eclipse project files
waffle-shiro: add tests
waffle-shiro: apply EPL license headers to new java source files
changelog: update for addition of shiro integration
Updated CHANGELOG.