slnkcctr.cpp: Removed some obsolete unreachable code
slnkcctr.cpp: Added info comments
slnkcctr.cpp: Added comment to extraction of frame from camera (it is a blocking call)
slnkcctr.cpp: Added FPS display (overlayed in source window)
slnkcctr.cpp: Changed controls window to WINDOW_NORMAL (resizeable)
DetectorColor::detect: Return invalid position when detection fails
FrameObject: Now supports invalid state
Use parameter `valid` to set validity of object.
Adjusted DetectorSlinky for the change.
slnkcctr.cpp: Catch invalid option name exception
Added BeatEstimator with basic hard-coded functionality
Modified FrameAnnotation and FrameObject to expose the position to support the new beat estimator.
Program now prints "." every time beat is detected with the first detector.
slnkcctr.cpp: Clarified an informative comment
slnkcctr.cpp: Added an info comment
FrameObject: Added `printCsv` for printing into CSV files
FrameAnnotation: Added function `printCsv` for printing into CSV files
slnkcctr.cpp: Prints detected slinky positions into "record.csv"
Ignore the output file "record.csv".