jsonb - path

This is an attempt to summarize What I think is now the lone outstanding 
jsonb issue.

We need to remove the ambiguity with jsonb_delete() by renaming the 
variant that takes a text[] (meaning a path) as the second argument to 
jsonb_delete_path. That seems uncontroversial.

We need to rename the corresponding operator from'-' to, say, '-#', or 
alternatively remove it. The question is which.

Future plans that might affect this issue: possible implementations of 
Json Pointer (rfc 6901), Json Patch (rfc 6902) and Json Merge Patch (rfc 
7396). The last one is on this list for completeness - it seems to me a 
lot less useful than the others, but I included it because Peter felt 
strongly about the lack of recursive merge. Json Patch could probably 
stand on its owm once we have Json Pointer, so that's really the thing 
we need to talk about. Undeneath the hood, I think we could make 
json_pointer be simply an array of text. If we did that, we could make 
an implicit cast from text[] to it,  and we could also have the input 
routine recognize an input string beginning with '{' and parse it 
directly as an array of text, since a standard json pointer expression 
has to being with '/' unless it's completely empty. Given all of that, I 
think, fingers crossed, it should be fairly safe to change the signature 
of all the functions and operators that currently take text[] as their 
path parameter to take a json_pointer instead without causing too much 
grief.

Proceeding from that, I'm rather inclined to say that the answer is to 
rename the operator rather than remove it, and that's what I'm going to 
do unless there's a groundswell that says no.

We should also in 9.6 provide an operator or function that removes all 
the named top-level keys. That operator's function would not be a json 
pointer, but an array of key names.

cheers

andrew