removed some warnings
Merge branch 'pr/57'
move PushAppId and masterSecret to Sender level
remove private PushApp and secret fields from builder
Merge branch 'pr/58'
bump to aerogear-parent and bom 0.2.9
Adding static methods for the Builders.

JIRA: https://issues.jboss.org/browse/AGPUSH-1099
General clean up.

* Adding builder methods that take String...
* Making field final
* Making constants strings for attribute map keys.
* Updated javadoc example.
* Fixing javadoc warnings.
javadoc warnings.
Merge branch 'suggestion-for-message-builders'