Node module and search module should be fully db_rewrite_sql'ed

Issue Summary

While implementing a system like the "domain module" (one node table for many sites and a custom node access system), I noticed that I can't "close" some search related issues to a site where the search is actually issued (or the search update index is run).

Problems I've found so far:

- in the node.module the 'status' operation of the search hook there are two queries that should be db_rewrite_sql()ed
- same thing in the update_index hook: the query range should be db_rewrited()

I file this one on the D7 branch, because I think that if it was addressed it won't on the D6 one :)

Sorry if it is a dupe; can't find a related one.