multiple query types

I propose that we face up to the issue of query type, and try to come to a
consensus within the TC, to present to the rest of the world.

I suppose everyone agrees that the "new" SRU should support multiple query
types.  Right? We never decided how to do it, but we did talk alot about it.
To review, there are two basic approaches: a query-type parameter, or a
separate parameter name for each query type.  More specifically and fleshing
this out, there are four approaches:

(1) use the query parameter to carry queries of all types and add a
queryType parameter to specify how the query is to be interpreted.  Explain
records list the types of queries supported by the server.

(2) use the name of the query parameter itself to indicate the type of
query.  For instance,  the current query parameter (for the CQL query) might
be renamed CQLQuery and a new query parameter of luceneQuery might be
specified to support Lucene queries. (No 'query' parameter, and no
'queryType parameter.)

(3) Use (1) with the additional stipulation that queryType is optional, and
it defaults to CQL.

(4) Use (4) except there is no standard default, the default is sever
dependent and exposed via explain.

For discussion at (and before) Monday's call.

--Ray