Update readme.md

Updates the jsp url for the sample usage in JSP

- updated some links
- removed some broken links

Fixed some typos in comments

Update JDBC file naming in MySQL setup instruction

fix typo

Petclinic doesn't work with Java 8

so we always use the latest in the classpath

RSS is becoming outdated, JSon is a better example

- added json-path to pom.xml
- added a simple test for Veterinarians

Happens since introduction of new mvc namespace tag for
content-negotiation