ns_getconfig - Configuration parameters (read/write)
This is an experimental read/write version of the ns_config command. Configuration parameters are read from a central store and cached per-thread. Parameters which are updated are pushed to the per-thread caches by the updating thread. Reads should be relatively cheap and uncontended.
Returns the value of the parameter key in section. If key is not given then return a list of all keys in the section. If section is not given then return a list of all known sections.
Update an existing configuration parameter, or if one does not already exist, create one...