Rebuild formhistory script on reload and do not leak the script
Rebuild formhistory script on reload and do not leak the script

1. Don't leak the script in formhistory_window_object_cleared_cb ()
2. Disconnect add-tab signal in the right place
3. Rebuild the base javascript code on extension reload


dokidokivisual/midori,dokidokivisual/midori,dokidokivisual/midori,dokidokivisual/midori,dokidokivisual/midori