Merge pull request #275 from serac/CAS-1305

CAS-1305 Restore jstl and standard taglib dependencies.
Merge pull request #276 from serac/CAS-1053

CAS-1053 Switch to Spring EL for parsing Webflow expressions.
Merge branch 'master' of github.com:Jasig/cas into CAS-1219
CAS-1219 Factor out SSO end actions into separate component.

The actions required to end the CAS SSO session have been factored out into
a common component, TerminateSessionAction, that is called from both login
and logout flows at the appropriate time.