^hell://meta/([0-9A-Z]{102})/([^/]+)/(.*)(/.*)$
$1: public key hash
$2: meta name
$3: JPath to meta content
name: Any string, contents' filename
key: hex number, symmetric encryption key
JSON structure (meta content with possibly applied JPath).
When updating, client should first check the date; if it's bigger than his current metatree, checks if signature is valid. If it's ok, then it replaces its own metatree with one available under given link.