[SR-Dev] script parsing: string switch support

[Juha Heinanen]

Jan Janak writes:

 > OK, so if the script writer writes something like:
 > 
 >   switch(@from.uri.user) {
 >   case "abc": ...
 >   case 100: ...
 >   case "foo" ..
 >   }

i my opinion it is unnecessary to allow such a mix of case label types.
reporting an error is an appropriate thing to do.

-- juha