provide cache controll for several responses

[hknochi]

Add Cache-Control headers to all listed functionalities:

• News: uncached
• Canteen: 7d /Overview (30d)
• Mail: uncached
• info/XXX: 10d
• timecal: 1d
• QIS: uncached
• Rooms: uncached

(...., HttpServletResponse response)
response.setHeader("Cache-Control","no-store, no-cache, must-revalidate");

Cache-Controll: public, max-age: TIME_IN_SECONDS

[hknochi]

skipped until spring boot 1.3.0 release