Made yii2-dev composer.json more lightweight

Do not depend on all packages, suggest them instead. require-dev will still have them for testing.

composer.json

@@ -68,16 +68,32 @@
 		"php": ">=5.4.0",
 		"ext-mbstring": "*",
 		"lib-pcre": "*",
-		"yiisoft/jquery": "1.10.*",
 		"yiisoft/yii2-composer": "*",
+		"yiisoft/jquery": "1.10.*",
 		"phpspec/php-diff": ">=1.0.2",
 		"ezyang/htmlpurifier": "4.5.*",
-		"michelf/php-markdown": "1.3.*",
+		"michelf/php-markdown": "1.3.*"
+	},
+	"require-dev": {
 		"twbs/bootstrap": "3.0.*",
+		"ext-curl": "*",
+		"ext-mongo": ">=1.3.0",
+		"ext-pdo": "*",
+		"ext-pdo_mysql": "*",
 		"smarty/smarty": "*",
 		"swiftmailer/swiftmailer": "*",
 		"twig/twig": "*"
 	},
+	"suggest": {
+		"twbs/bootstrap": "required by yii2-bootstrap, yii2-debug, yii2-gii extension",
+		"ext-curl": "required by yii2-elasticsearch extension",
+		"ext-mongo": "required by yii2-mongo extension",
+		"ext-pdo": "required by yii2-sphinx extension",
+		"ext-pdo_mysql": "required by yii2-sphinx extension",
+		"smarty/smarty": "required by yii2-smarty extension",
+		"swiftmailer/swiftmailer": "required by yii2-swiftmailer extension",
+		"twig/twig": "required by yii2-twig extension"
+	},
 	"autoload": {
 		"psr-0": {
 			"yii\\bootstrap\\": "extensions/",