Template: add support for dictionary names in tag names.
Template: add support for dictionary names in tag names.

This patch makes it possible to write '{<dictionary>:<tag>}' as the tag
name. This will load the given dictionary and fetch the given tag from there.

vivekrajenderan/simplesamlphp,vivekrajenderan/simplesamlphp,vivekrajenderan/simplesamlphp,tectronics/simplesamlphp,vivekrajenderan/simplesamlphp,tectronics/simplesamlphp,tectronics/simplesamlphp,tectronics/simplesamlphp,tectronics/simplesamlphp,vivekrajenderan/simplesamlphp