atools: New option for astcopy to specify class of output object

See new parameter CLASS.
atools: asttran2 now writes the last position to output parameters
atools: astunformat now writes the unformatted value to an output parameter
smurf: new command "jsajoin" to combine JSA tiles into a TAN-projected NDF

The command is implemented in a python script at the moment. The
effectiveness of the resampling may require more checking.