Converted the extract() function to the new design.
Converted the execute() function to the new design.
Created the 2 new API functions: first_residue_num() and last_residue_num().
Converted the create_script() function to the new design.
Converted the create() function to the new design.
Fixes for the Dasha user function print outs.
Missing import bug fix.
This was identified by the arg unit tests of 7597.
Created 7 arg unit tests for all fns of the dasha user function class.
Converted the Dasha user function class prompt interface to the new design.
Converted all the Dasha class methods into module functions.