Roughed in autoscaling instance record and cleanup.

Functionality for building list of members, instances, etc
for queries about specific ones is all essentially the same
so also extracted that into its own function (member_params/2).
Basic autoscaling instance desciption call.

Also corrected an oversight whereby NextToken in all of the
describe calls was always being passed forwards to the actual
AWS calls as a parameter with value 'none'.  Now gets
dropped when it's 'none' via pattern matching in the function
definitions.