cachedb_mongodb: fix sorting results for mongo queries
cachedb_mongodb: handle _id based queries
cachedb_mongodb: complete previous commit - handle _id based queries
improve docs
Proper reporting for invalid module parameter types
allow route_to_gw() to receive a list of gw IDs (instead of only one) - the list is a comma separated list of gw IDs
docs updated for route_to_gw()
Job timeout for the 'exec' module

* the "time_to_kill" parameter now works for all "exec_*" commands
* improved overall documentation and usage examples