<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
When I read the `copy` documentation, I couldn't work out what it meant.  Unfortunately, this meant it sounded like it might be a weird sex joke.

It doesn't sound like a big problem, but in an ideal world, I think we should prefer to avoid weird sex jokes in an alias for a parameter called `force`.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
copy

##### ADDITIONAL INFORMATION
Issue search tells me "thirsty" was added as an option to the `get_url` module.  In that context, it is appropriate.  But in the context of the `copy` module, it does not make sense, because `copy` only works in the upload direction.

The first three pages of Google Search results (Ansible thirsty) show people using "thirsty" for downloads only, not uploads.  Similarly for GitHub code search (copy thirsty language:YAML).
param = self.params
        if legal_inputs is None:
            legal_inputs = self._legal_inputs
        for k in list(param.keys()):
            if check_invalid_arguments and k not in legal_inputs:
                unsupported_parameters.add(k)
        for k in PASS_VARS:
            
            param_key = '_ansible_%s' % k
            if param_key in param:
                if k in PASS_BOOLS:
                    setattr(self, PASS_VARS[k][0], self.boolean(param[param_key]))
                else:
                    setattr(self, PASS_VARS[k][0], param[param_key])
                
                if param_key in self.params:
                    del self.params[param_key]
            else:
                
                if not hasattr(self, PASS_VARS[k][0]):
                    setattr(self, PASS_VARS[k][0], PASS_VARS[k][1])
        if unsupported_parameters:
            msg = "Unsupported parameters for (%s) module: %s" % (self._name, ', '.join(sorted(list(unsupported_parameters))))
            if self._options_context:
                msg += " found in %s." % " -> ".join(self._options_context)
            msg += " Supported parameters include: %s" % (', '.join(sorted(spec.keys())))
            self.fail_json(msg=msg)
        if self.check_mode and not self.supports_check_mode:
            self.exit_json(skipped=True, msg="remote module (%s) does not support check mode" % self._name)
    def _count_terms(self, check, param=None):