fix(ngResource): stop /. collapsing affecting parameter values

The ngResource documentation states: "If the parameter before the suffix
is empty, :resource_id in this case, then the /. will be collapsed down
to a single .. If you need this sequence to appear and not collapse then
you can escape it with /\..". This means that ngResource should not
collapse a "/." sequence if the "." comes from a (non-empty) parameter
value that happens to start with a ".".