SecurityService cache turned off by default

The check for if a user has permission to use a tool is fired each time the tool is placed in an iframe for display.

The SecurityService has the ability to cache this query, but it is turned off by default.

https://source.sakaiproject.org/svn/trunk/sakai/legacy/legacy-components/src/webapp/WEB-INF/components.xml
https://source.sakaiproject.org/svn/branches/sakai-maint/legacy/legacy-components/src/webapp/WEB-INF/components.xml

<bean id="org.sakaiproject.service.legacy.security.SecurityService"
class="org.sakaiproject.component.legacy.security.SakaiSecurity"
init-method="init"
destroy-method="destroy"
singleton="true">
<property name="logger"><ref bean="org.sakaiproject.service.framework.log.Logger"/></property>
<property name="cacheMinutes"><value>0</value></property>
</bean>