package/nss-myhostname: Add package

package/nss-myhostname: Add package

nss-myhostname is helpful to resolve local hostname without domain.
For instance, if we set hostname to myboard and ping myboard
without .local suffix, it fails if /etc/hosts stays unchanged.

nss-myhostname modifies /etc/nsswitch.conf file.
It set myhostname resolution just after files in hosts line,
for example:
    hosts: files myhostname mdns4_minimal [NOTFOUND=return] dns

This choice comes from Debian commit [1] and Yocto recipe [2].
Also, nss-myhostname author suggests myhostname should be used as
a backup and appended at the end of hosts line. Both choices are valid.

Discussion on Debian bug tracker [3] gives some details on issue
that may occurs using nss-myhostname (see fqdn).

Note nss-myhostname is already included in systemd, so ensure is conflicts
with it.

[1] http://git.nomeata.de/?p=libnss-myhostname.git;a=commit;h=5104d7f0045df55ee8be526e8c84078750e1e0ed
[2] https://git.yoctoproject.org/cgit.cgi/poky/plain/meta/recipes-support/nss-myhostname/nss-myhostname_0.3.bb
[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=756224

[Peter: simplify sed invocation, adjust Config.in]
Signed-off-by: Vincent Prince <vincent.prince.fr@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>