webdm apparmor denials

[Jamie Strandboge]

From snappy-dev@:
Apr 24 00:53:32 localhost kernel: [65181.037479] audit: type=1400
audit(1429836812.172:11): apparmor="DENIED" operation="open"
profile="webdm.canonical_avahi_0.5"
name="/proc/sys/net/core/somaxconn" pid=1985 comm="metabin"
requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Apr 24 00:53:32 localhost ubuntu-core-launcher[1985]: 2015/04/24
00:53:32 gmx: unable to open local socket: listen unix
/tmp/snaps/webdm.canonical/0.5/tmp/.gmx.1985.0: bind: no such file or
directory

These rules should be added to the apparmor policy:
  @{PROC}/sys/net/core/somaxconn r,
  /tmp/snaps/@{APP_PKGNAME}/ r,
  /tmp/snaps/@{APP_PKGNAME}/** rk,
  /tmp/snaps/@{APP_PKGNAME}/@{APP_VERSION}/ rw,
  /tmp/snaps/@{APP_PKGNAME}/@{APP_VERSION}/** mrwlkix,

Note: something needs to still create /tmp/snaps/@{APP_PKGNAME}.