Fixed reporting, to_i seems to be broken on JRuby+Truffle

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Step-by-step move all benchmarks into benchmarks directory

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Removed vms_experiment's mandelbrot.rb, will use JRuby variant instead

- JRuby's variant does not print, but gives a sum value that can be checked for correctness. Otherwise, the implementation looks identical

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Adopt vms_experiment's richards.rb

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Added ReBench-compatible harness and correctness check to richatds.rb

Signed-off-by: Stefan Marr <git@stefan-marr.de>