rouziclib edition (fully working)

[Photosounder]

You should really enable Issues as the original had a compilation problem with mecParserBase.cpp which I fixed.

Anyway I added rouziclib, it ranks about in the middle in performance (but faster than most in Debug). It doesn't accept expressions that start with "+a" and seems like it gives the wrong results on things like -1^0 (is there an easy way to see the bogus results in the logs?). I didn't make an MPFR version, but it can be done, although this is probably rather pointless since the bulk of MPFR execution would be inside MPFR, not the interpreter's overhead, and the MPFR precision would determine the speed.

More details at the top of the readme.md file, which you won't want to leave as I edited it.