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
fixup for a524e1654cc034e85bda048f16a706dbded29a90

inconsistencies/bugs in example payloads
a few more example payloads
added examples for /testdrives/:token
testdrives started through POST /testdrives

... previously POST /appliances/:app/:version/:format
examples for /cron, /cron/:job
examples for /software/:app/banned
examples for /repositories
/gallery/:app incl. examples
/gallery/:app/:version incl. examples
/gallery incl. examples
/gallery/:app/rating incl. examples
/gallery/:app/comments incl. examples
/appliances includes examples
/appliances/:app incl. examples