enable --template when using --daemon

Enable --template to work with --daemon by translating the template to a "normal" update and executing that one.
Also enable the option to "strip" a leading path from RRD-update when running a rrd_cached operation by defining the environment variable RRDCACHED_STRIPPATH.

Both have bveen implemented to make it possible to use rrdcached with xymon.
This probably also may help Cacti.

This relates to: https://github.com/oetiker/rrdtool-1.x/issues/325

Thanks, Martin