Added nimrod version

https://github.com/Araq/Nimrod
Cmd line and output compatibility with go version.
go:

- write benchmark data into a json file
- accept all options as proper command line parameters
- extract the ART into a file, and read it in during runtime
- introduce concept of a RAYS_HOME (also settable via -h)
- make the creation of objects simpler by shifting the viewport (again, i know)
- various refactors
doc: RAYS_HOME
go: don't be stupid
go: clamp color values to a max of 255
go: collect and print memstats
c++: only clamp upwards
Updated nimrod version with new graphic
go: further simplify go object creation and shift it up a little
Removed comment
c++: generate the same scene as the ref go version
Merge pull request #21 from tkalbitz/java-upstream-java-go-catchup2

Cmd line and output compatibility with go version.
java: correct art
java: add missing line in art
java: get the image to match up to the reference go version
java: clamp pixel values to a max of 255
doc: add links to reference images
ruby: correct the art
ruby: make the sky color calculation linear (as per ref)