s3-mdssvc: add Spotlight-RPC implementations

The following Spotlight-RPC commands are implemented:
* fetchPropertiesForContext
* open query
* fetch query results
* fetch result attributes
* store attributes
* close query
* fetch attributenames

Also updated:
* mdssvc: add a state struct
* remove typedef slq_t, use struct sl_query instead
* fix all elements names of struct sl_query
* make a connection to Tracker
* add support functions for maintaining a list of active queries
* add hash table for query results
* add structure for ino to path mapping
* add MAX_SL_RESULTS and remove unused stuff

Signed-off-by: Ralph Boehme <rb@sernet.de>
s3-mdssvc: remove error checking macros

Signed-off-by: Ralph Boehme <rb@sernet.de>
s3-mdssvc: mdssvc_unknown1() arguments unkn5 and unkn6

unk5 contains the clients UNIX uid and unkn6 the gid.

Signed-off-by: Ralph Boehme <rb@sernet.de>
fixme: s3-mdssvc: handling of not indexed shares

Signed-off-by: Ralph Boehme <rb@sernet.de>
s3-mdssvc: open_query() Spotlight RPC error handling

Errors in Spotlight RPC functions must be returned a Spotlight RPC
data blob with a -1 uint64, not as an DCE/RPC error.

Signed-off-by: Ralph Boehme <rb@sernet.de>