[script] add __init__.py in each script package

script/scenarios/demos/talos_flatGround.py

 from hpp.corbaserver.rbprm.talos import Robot
 from hpp.gepetto import Viewer
-from display_tools import *
+from tools.display_tools import *
 import time
 from hpp.corbaserver.rbprm.rbprmstate import State,StateHelper
 print "Plan guide trajectory ..."

script/scenarios/demos/talos_navBauzil.py

 from hpp.corbaserver.rbprm.talos import Robot
 from hpp.gepetto import Viewer
-from display_tools import *
+from tools.display_tools import *
 import time
 from hpp.corbaserver.rbprm.rbprmstate import State,StateHelper
 print "Plan guide trajectory ..."

script/scenarios/demos/talos_navBauzil_hard.py

 from hpp.corbaserver.rbprm.talos import Robot
 from hpp.gepetto import Viewer
-from display_tools import *
+from tools.display_tools import *
 import time
 from hpp.corbaserver.rbprm.rbprmstate import State,StateHelper
 print "Plan guide trajectory ..."