Created and modified a few samples for better documentation 

1. New Jersey+Spring sample
2. New Mule sample
3. New RESTEasy+Spring sample
4. Modified RESTEasy sample

These will be used by the new wiki section for application set up.

@fehguy - I've slightly modified the pom.xml of the Jersey+Spring, RESTEasy+Spring and RESTEasy samples with regards to the new method of loading the swagger-ui. It now copies the files to the webapp dir in the */target* directory and does not affect the sources. 
This way, the source directory is not modified, and git doesn't see the new files being added (not requiring to commit and so on). If you find it better, you may want to modify the other samples as well. If you do it, make sure to run the samples and test them (with package jetty:run). I had an issue with the Spring samples which required an additional configuration line for the jetty plugin. Let me know if you want me to make the modification instead.