[MIR] libtirpc, rpcbind

The new nfs-utils in Debian adds dependencies on libtirpc and rpcbind for IPv6. One is a network-sensitive library and the other is a network server, so I guess we'll want some careful review.

== libtirpc ==
* Availability: Package is in universe, synced from Debian
* Rationale: Dependency of rpcbind which is required for IPv6 support
* Security:
** No CVE: http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=tirpc
** 2 old (2008) secunia advisories: http://secunia.com/advisories/product/17898/?task=advisories (fixed by upstream)
** Ubuntu CVE tracker: none
** SUID/SGID binaries: none
** Executables in sbin: none
** Daemons: none
* QA:
** Just a library with two binary packages (one for the lib and one -dev), no debconf question or configuration.
** No bug in Ubuntu: https://launchpad.net/ubuntu/+source/libtirpc/+bugs
** No critical bugs in Debian: http://bugs.debian.org/cgi-bin/pkgreport.cgi?repeatmerged=no&src=libtirpc
** Package is maintained in Debian though not very active (last upload in December, moved to testing in February)
** Currently Build-depends on universe package "libgss-dev" but isn't necessary. Next Debian upload will drop it.

== rpcbind ==
* Availability: Package is in universe, synced from Debian.
* Rationale: Replacement of portmap as a nfs-utils build-depend required for IPv6 support.
* Security:
** No CVE that seem to target the current code base: http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=tirpc
** No secunia advisories: http://secunia.com/search/?search=rpcbind
** Ubuntu CVE tracker: none
** SUID/SGID binaries: none
** Executables in sbin: /sbin/rpcbind (the daemon) and /usr/sbin/rpcinfo (a client)
** Daemons: rpcbind (sysvinit script, probably to be converted to upstart similar to what was done for portmap)
* QA:
** No debconf question, one config file in /etc (/etc/insserv.conf.d/rpcbind) but no user changes required
** No critical bugs in Ubuntu: https://launchpad.net/ubuntu/+source/rpcbind/+bugs
** No critical bugs in Debian: http://bugs.debian.org/cgi-bin/pkgreport.cgi?repeatmerged=no&src=rpcbind
** Package is maintained in Debian, last upload in March.
** Depends and build-depends on libtirpc (see MIR above)