devel: Removed timing measurements
devel: Added version requirements

Still missing for catch and cereal
devel: Simplified example
devel: Added notes on prerequirements [ci skip]
devel: Added setter for the maximal number of iterations
devel: Make use of the newly introduced setter (see previous commit)
fix: Added return type specifier
devel: Added additive separability threshold setter
devel: Added quadratic model residuals threshold

Still missing normalisation of residuals
devel: Added linear model residuals threshold
devel: Added default linear model residuals threshold