Experimental API tutorials

Various examples showing the experimental API.

Warning

This is part of the experimental API, which might change in the future. Feedback is welcome!

Topics
	RCanvas examples
	These are RCanvas examples.

Files
file	browser.cxx
file	concurrentfill.cxx
file	filedialog.cxx
file	fitpanel.cxx
file	fitpanel6.cxx
file	histops.cxx
file	perf.cxx
file	perfcomp.cxx
file	simple.cxx