Another batch of fixes

Another batch of fixes
 Correct error handling in DLPI [ISC-Bugs #20378]
 Remove __sun__ and __hpux__ typedefs in osdep.h as they are now being
 checked in configure.  [ISC-Bugs #20443]
 Modify how the cmsg header is allocated the v6 send and received routines
 to compile on more compilers.  [ISC-Bugs #20524]
 When parsing a domain name free the memory for the name after we are
 done with it.  [ISC-Bugs #20824]