Allow running native apps from other directories.

It isn't always safe to assume `./` is the app directory, and removing
that assumption opens up options.

Requires at least Haxe 3.4, but I don't think Lime supports 3.3 anyway.

templates/haxe/ManifestResources.hx

@@ -3,6 +3,7 @@ package;
 
 
 import haxe.io.Bytes;
+import haxe.io.Path;
 import lime.utils.AssetBundle;
 import lime.utils.AssetLibrary;
 import lime.utils.AssetManifest;
@@ -44,6 +45,8 @@ import sys.FileSystem;
 			rootPath = "";
 			#elseif console
 			rootPath = lime.system.System.applicationDirectory;
+			#elseif sys
+			rootPath = Path.directory(Sys.programPath()) + "/";
 			#else
 			rootPath = "./";
 			#end