Detecting strings is a bit harder than just looking for the string
attribute, so make sure to use the function which has the purpose of
doing just that.

Fixes compilation of generated server/proxy code when a parameter has
both the [out] and [string] attributes.

The resolv.h header file won't compile without netinet/in.h being
included first.

Change the remaining text conversions to use the Unix CP as the
strings come from system library functions.

If any ancestor of an interface needs delegation, the interface itself
has holes in the vtables and thus needs delegation, too.

Fixes regression caused by ce06de42
Amount of time per buffer was doubled, but amount of buffers wasn't 
halved, so latency was doubled.

The pointers to r1 and r2 are already PDNS_RECORDs.