Improve how the end timestamp of a history facility is fetched.

Instead of requesting the whole index file of a history facility and
move on to the abstract of the last history raw data file in order to
get the end timestamp of it, the newly supported "-n 0" option of the
historyQuery handler can be manipulated to return the start and end
timestamp of a history facility directly.
Update the path of configuration files in a couple of .md documents

Update the path of configuration files according to the current status
of the ONEDC/obix.git repo, also fix the name of the generic configuration
file with an oBIX server that can be utilised by different adaptors.