Correcting benchmark for better correctness

- Better correctness in the benchmark (removing uneeded names, modifiers, etc.)
- Removing special exponent optimization, which was just a test. It appears,
using all the Scala Library as tests, that our first implementation is better.
Fix ambiguous sentence + first sbt command attempt

- Ambiguous sentence in the ratio.sh file
- first attempt to design a command, trying to add settings to an existing
project definition (for now for testing, not to automate the use of the
NSC plugin). Unfortunately doesn't work.

See :
https://stackoverflow.com/questions/23665496/compile-with-different-settings-in-command