Added preset, autostop, and IR on/off support

This patch allows toggling of the IR LEDs using the wake/sleep buttons. It also adds support for the camera presets. 

Most importantly (for me at least) it adds support for autostop. My home network lags enough when I am off-site that the continuious movement is almost impossible for me to use. With this patch the camera will autostop movement if the Auto Stop Timeout is set to a non-zero value. Set it to zero and it will move continuously until the stop button is hit.

Even though the 8908 and 8918 don't support them, I'm tempted to add support for focus, iris, and zoom. That would allow this module to work for any Foscam IP Camera that supports their CGI sdk. (http://www.foscam.es/descarga/ipcam_cgi_sdk.pdf) I would just need to figure out the functions that ZM calls to activate those functions, although I would have no way of testing them.