Connection::receive() gets a function parameter. Id it's not empty,
calls that instead of the instance's callback.
New command to take a picture and process it.
Can find led on image taken with phone. (More-or-less stable.)
Fix file was left out from previous commit.
Merge branch 'master' into ts_findLed

Conflicts:
	include/SMEyeLDesktop.h
	src/SMEyeLDesktop.cpp
Add disconnect command.
Merge branch 'master' into ts_findLed

Conflicts:
	src/SMEyeLDesktop.cpp
Nice solution to have separate threads for separate ImageHelper
instances (with different window names), but unfortunately doesn't work
because OpenCV's window implementation doesn't support multithreading.
This is just for documentation.
Revert to single threaded ImageHelper (though still on a separate
thread than main). Can create new window by calling
ImageHelper::get()->show(cv::Mat&, std::string) with a new string or
refresh the previous image by a second call to this using the same
window name.
Add documentation for nearly all of the classes.