[Users] Faster to do avp_printf();avp_check OR search()?

[Juha Heinanen]

Daniel-Constantin Mierla writes:

 > If you want just to check if there is a Refer-To header, you can use the 
 > function is_present_hf() from textops module. This is the fastest way to 
 > check if a header exists.

this reminds me about the thing that is_present_hf() implementation is
not very efficient, because it compares header names as strings.  this
could be turned into type comparison with aid of a fixup function (for
all hfs known to ser).

-- juha