RPC: support embedded tomcat7 to run Perun locally

- You can now run Perun locally by "mvn tomcat7:run-war" in /perun-rpc folder.
- You still need configuration files in /etc/perun (e.g. taken from devel).
- If you don't use own DB, start SSH tunnel to devel DB before running RPC.

- In order to actually get response from Perun (other than exception) you must
  setup Apache web server to provide (or fake) authz in AJP headers and
  it must rewrite external http request to internal ajp request.

  Example Apache configuration file is on internal redmine wiki.

- HTTP and AJP ports are both started (did't find way to disable unnecessary HTTP port).
  But you will never get proper response from HTTP port since it will
  be missing AJP header for authentication provided by Apache.