simplify mu-plugin management

the Drop-in mechanism does not need to specify a file-name, in which case it copies all files (excluding readme.txt and similars). Slightly less stuff to write in this case: plugins which declare themselfs to be mu-plugins will be handled automaticaly, the ones which do not have to be listed twice.

More-privacy-option plugin actually ships with other files (translations), so it should not be considered a mu-plugin, but installed network wide as a regular plugin.

composer.json

@@ -121,11 +121,10 @@
         "wordpress-install-dir": "app/wp-core",
 	"installer-types": ["bower-asset", "npm-asset"],
         "installer-paths": {            
-            "vendor/{$name}": [
+            "mu-plugins-tmp/{$name}": [
                 "wpackagist-plugin/hyperdb",
                 "wpackagist-plugin/disable-wordpress-updates",
                 "wpackagist-plugin/wpmu-new-blog-defaults",
-                "wpackagist-plugin/more-privacy-options",
                 "wpackagist-plugin/disable-emojis",                
                 "type:wordpress-muplugin"],
             "app/wp-core/{$name}": ["type:wordpress-dropin"],
@@ -138,12 +137,10 @@
         "patches-file": "composer.patches.json",        
         "dropin-paths": {
             "app/wp-core/wp-content/mu-plugins" : [
-                "package:wpackagist-plugin/disable-wordpress-updates:disable-updates.php",
-                "package:wpackagist-plugin/wpmu-new-blog-defaults:cets_blog_defaults.php",
-                "package:wpackagist-plugin/more-privacy-options:ds_wp3_private_blog.php",
-                "package:wpackagist-plugin/disable-emojis:disable-emojis.php",
-                "package:noblogs/ai-mu-plugins:embed.php,remove-password-change-notification.php,send-smtp-email.php",
-                "package:noblogs/noblogs-wp-ssl:noblogs-wp-ssl.php"
+                "package:wpackagist-plugin/disable-wordpress-updates",
+                "package:wpackagist-plugin/wpmu-new-blog-defaults",
+                "package:wpackagist-plugin/disable-emojis",
+		"type:wordpress-muplugin"
             ],
 	    "app/wp-core/wp-content/themes" : [
 		"package:noblogs/themes-child"