Started overall project refactoring

1. Git will now be ignoring files whose names start with `exp_`.
   If you want to do quick experimenting but are not ready to add
   such files to repository, name them starting with `exp_`. For
   example `exp_cool_motion.py`.
2  Use the file `nao_defaults.json` to store the global project
   settings (such as IP address of the robot, or our preferred
   resolution). In your scripts make sure to load the default
   values from that file if needed (i.e. do NOT hard-code any
   configuration in your scripts). `nao_defaults.json` is a file
   with the stable config. If you need to experiment with configs,
   create a file `exp_config.json`.
3. Colorpicker is now a saner tool (you can specify output width, and
   the default IP address of the nao is pulled from the JSON config
   file).

scripts/nao_defaults.json

@@ -0,0 +1,6 @@
+{
+    "ip": "192.168.0.11",
+    "res": 1,
+    "port": 9559,
+    "cam": 0
+}