[RT] Improved resource (provider) api

[Carsten Ziegeler <cz...@apache.org>]

Hi,

the resource api has not that much changed in the past years, which is a
good sign. However, over time we added new features which lead to a
rather complicated resource provider api. We also found out that some
design decisions prevent from faster implementations or scaling the
solution.
In addition, there are some areas were we don't have a good abstraction
yet and implementing the api for other resource providers than jcr is a
pain.
In the past weeks I've been working on a prototype for a new resource
provider api and some additions to the consumer api. One main goal is to
keep it compatible for users of the resource api.

I've split it up in three different sections:
- new resource provider api and handling
- new observation handling
- new query api

I'll start a separate discussion for each of these topics, although I
think we should tackle them together. And this is just a first draft, so
nothing is carved in stone.

Regards
Carsten
-- 
Carsten Ziegeler
Adobe Research Switzerland
cziegeler@apache.org