#56 started, refactoring

- changed Spring Security config from xml to Java-config (class
gmm.SecurityConfiguration)
- moved css folders around (moved shared folders into all folder)
- seperated css for tasks page task list from css for each task in the
list (needed for public list with linked tasks)
- refactored all html & javascript links to include link to pageContext
(also using <c:url />)
- created public dummy page in preperation for #56 with name links.jsp
- web.xml scans complete gmm package for configuration classes now