overview: updated some RFC numbers

* 2068 has been obsoleted by 2616 long ago, dunno how
  the old number got in.
* application/json-patch is Standards Track RFC 6902.
* application/json-pointer is Standards Track RFC 6901.
fixup for c1f5d76f22ca298d578992b57ae53532893b11fe

bad link to /appliances/:app/configuration
tweaks in the appliance-configuration schema

package, patterns lists are easier to work with as hashes
with package/pattern names as keys.
/appliance/:app/configuration: example payloads