Minor bug fixes to tomcat role

 * Added ignore errors to tomcat restart to get around the stupid
   fake script problem.
 * Added tomcat7-admin to installed packages so that it always
   installs the manager, not just under ideal conditions.
 * Some parameter optimisations to the tomcat config that Chris
   recommended

Ticket: #5507

Signed-off-by: Nathan Callister <ncallister@iwsoftware.com.au>