get_camera_image() is too impatient

[touretzkyds]

In aim.py, when get_camera_image() starts the image stream, it will throw an exception and exit if the first camera image doesn't arrive within 0.5 seconds. This is way too impatient, and often causes my code to fail on startup.

A more reasonable threshold would be 2 seconds, although I'd suggest using 5 seconds to be really safe.

It would also be good practice to make this a variable that users can control, instead of a mysterious constant.

[touretzkyds]

I've submitted a pull request to fix this.