Create an argument for functions that set buttons that does not automatically default to false

[ximk]

Currently, setting buttons/sticks through these functions causes all the items in the dictionary that are not specified to default to False (buttons) / neutral (sticks). This can be a massive headache for script writers when the script is only designed to modify one or two values. There is a workaround, but it is messy, and ideally we would simplify the process.

[vabold]

Before doing this, we should ensure that the dict is initialized before diff calls like this are allowed.