Use "$@" for arguments

Related to #2306

std/tools/haxedoc/haxedoc.sh

@@ -1,2 +1,2 @@
 #!/bin/sh
-haxe --run tools.haxedoc.Main $@
+exec haxe --run tools.haxedoc.Main "$@"

std/tools/haxelib/Main.hx

@@ -852,7 +852,7 @@ class Main {
 						var file = haxepath+'haxelib';
 						try File.saveContent(
 							file,
-							'#!/bin/sh\nhaxe '+args.join(' ')+' --run tools.haxelib.Main $@'
+							'#!/bin/sh\nexec haxe '+args.join(' ')+' --run tools.haxelib.Main "$@"'
 						)
 						catch (e:Dynamic) 
 							throw 'Error writing file $file. Please ensure you have write permissions. \n  ' + Std.string(e);