OZP-737: Externalize OWF and Rest security context xml files.

1. Modified distribution and deployment builds to include the security beans and context files in their etc/security folders.
2. Added the RESTsecurityContext.xml to the external ozone-security-contexts folder and updated OWFsecurityContext.xml.
3. Changed distribution to pull in the security bundle and unpack its files in etc/security.
4. Added line to set sever.home system property when running in tomcat inside WebAppListener.java and modified the test accordingly to ensure it gets set properly.
5. Added a server.home entry in karaf's system.properties file.