Typo3 backend module form error - typo3

Question

I have no idea why, but the error just disappear without any changes. Now it works. I have not change anything. (I deleted cache many times so it cannot be because of the cache)
Problem
I created an extension using extension builder (if anyone knows any good documentation please give me link because official documentation does not have any examples).
I have a form and when I submit the form I have the error
TYPO3 v4.7
The action "formSave" (controller "Promoters") is not allowed by this plugin. Please check Tx_Extbase_Utility_Extension::configurePlugin() in your ext_localconf.php.
I created ext_localconf.php according to typo's wiki.
Form code
<f:form action="formSave" name="" object="">
<f:form.textfield id="emailResendInterval" name="emailResendInterval" value="" />
<f:form.textarea cols="30" rows="5" id="emails" name="emails" value="" />
<f:form.submit name="submit" value="Save" />
</f:form>
ext_localconf.php
<?php
if (!defined ('TYPO3_MODE')) die ('Access denied.');
$GLOBALS['TYPO3_CONF_VARS']['EXTCONF'][$_EXTKEY] = unserialize($_EXTCONF);
if ($GLOBALS['TYPO3_CONF_VARS']['EXTCONF'][$_EXTKEY]['registerSinglePlugin']) {
// fully fletged blog
Tx_Extbase_Utility_Extension::configurePlugin(
$_EXTKEY, // The extension name (in UpperCamelCase) or the extension key (in lower_underscore)
'Promoters', // A unique name of the plugin in UpperCamelCase
array ( // An array holding the controller-action-combinations that are accessible
'Promoters' => 'configuration,formSave', // The first controller and its first action will be the default
),
array( // An array of non-cachable controller-action-combinations (they must already be enabled)
)
);
} else {
Tx_Extbase_Utility_Extension::configurePlugin(
$_EXTKEY, // The extension name (in UpperCamelCase) or the extension key (in lower_underscore)
'Promoters', // A unique name of the plugin in UpperCamelCase
array ( // An array holding the controller-action-combinations that are accessible
'Promoters' => 'configuration,formSave', // The first controller and its first action will be the default
),
array( // An array of non-cachable controller-action-combinations (they must already be enabled)
)
);
PromotersControler
class Tx_Promoters_Controller_PromotersController extends Tx_Extbase_MVC_Controller_ActionController {
/**
* action configuration
*
* #return void
*/
public function configurationAction() {
}
/**
* action formSave
*
* #return void
*/
public function formSaveAction() {
}
}

Answer 1

Seems fine actually, I'm not sure about the if statemant in the localconf though. Please try this:
<?php
if (!defined ('TYPO3_MODE')) die ('Access denied.');
// fully fletged blog
Tx_Extbase_Utility_Extension::configurePlugin(
$_EXTKEY,
'Promoters',
array (
'Promoters' => 'configuration,formSave',
),
array(
)
);
?>