- Fixed errors/violations noticed by PHPMD and PHPCS

- Removed parameter perform_sql from public method controllers/system/extensions/CLI_Manager->installExtension
- Added new public method controllers/system/extensions/CLI_Manager->installExtensionNoSQL
- Improved code quality in controllers/system/extensions/Manager->toggleExtension
- controllers/system/extensions/Manager->uploadExtension better check of
  HTTP POST parameter notPerformSql
- application/views/system/extensions/manager.php renamed checkbox
  performSql to notPerformSql
- application/views/system/extensions/tableWidget.php removed PHP close
  tag at the end of the file
- Improved code quality in application/widgets/TableWidget.php
- Removed private method _getColumnsNames from application/widgets/TableWidget.php
- Improved code quality in application/libraries/ExtensionsLib.php
- Added new private methods _getExtensionsPath and _getUploadPath to application/libraries/ExtensionsLib.php
- Changed application/libraries/ExtensionsLib->_toggleExtension to public method toggleExtension
- Removed private properties UPLOAD_PATH and EXTENSIONS_PATH from application/libraries/ExtensionsLib
- Added use imports in application/libraries/ExtensionsLib
- application/libraries/ExtensionsLib->installExtension changed parameters default values

application/views/system/extensions/tableWidget.php

@@ -32,7 +32,7 @@
 			'Dependencies',
 			'Enabled'
 		),
-		'formatRow' => function($datasetRaw) {
+		'formatRow' => function ($datasetRaw) {
 
 			if ($datasetRaw->{'description'} == null)
 			{
@@ -91,5 +91,4 @@
 	);
 
 	echo $this->widgetlib->widget('TableWidget', $tableWidgetArray);
-?>