Added few files to OSX.gitignore

Ignore files generated by OS X that might appear on external disks:
  .Spotlight-V100
  .Trashes

Global/OSX.gitignore

@@ -4,6 +4,10 @@ Icon?
 # Thumbnails
 ._*
 
+# Files that might appear on external disk
+.Spotlight-V100
+.Trashes
+
 # ack & vim swap files
 .ackrc
 *.swp