Send form and form_state to variables to form generation functions

[signalpoint]

Right now when a developer creates a form, they do so like this:

/**
 * Define the form.
 */
function my_module_say_hello_form() {
  var form = {
    'elements':{
      'name':{
        'type':'textfield',
        'title':'Your name',
        'required':true,
      },
      'submit':{
        'type':'submit',
        'value':'Say Hello To Me',
      },
    },
  };
  return form;
}

Instead, we need the function to take in the form and form_state (just like Drupal!), that way developers will modify the form and return the form, not create the form and return it. This will be the correct code to use:

/**
 * Define the form.
 */
function my_module_say_hello_form(form, form_state) {
  form.elements.name = {
    type:'textfield',
    title:'Your name',
    required:true,
  };
  form.elements.submit = {
    type:'submit',
    value:'Say Hello To Me',
  };
  return form;
}

We need to do this so default values like form.validate and form.submit will already be available when a developer is building a form. See https://api.drupal.org/api/drupal/modules%21system%21system.module/function/system_settings_form/7 for an example of why DG's implementation of system_settings_form() needs the form.submit set first.