Fix apply_scopes to allow further refinement of result

[enwood]

apply_scopes should be sending scope to result, not to self, to allow for repeated calls (further refinement) when multiple scope parameters are passed. e.g.

http://localhost:3000/admin/entities?status=active&entity_type=corporation

scopes.merge!(status_is: params[:status])
scopes.merge!(entity_type_is: params[:entity_type])

Further details: https://groups.google.com/forum/?hl=en#!topic/hobousers/EtgRMr1RAUE

[iox]

Thanks Tim!