provide a mu script to optimize virtuoso configuration

[nvdk]

See https://github.com/mu-semtech/mu-cli#writing-your-own-script on writing scripts. We should provide a script that allows users to optimize their configuration.

This script could either calculate or ask the amount of memory available and the size of the database and optimize at least the following parameters based on that:

MaxCheckpointRemap should be 1/4 of the database size
NumberOfBuffers maximum should be about 60-70% of the available memory, count 9KB per buffer
MaxDirtyBuffers should be about 75% of NumberOfBuffers

More info on
http://docs.openlinksw.com/virtuoso/checkpointparams/
http://docs.openlinksw.com/virtuoso/sampleconf/
http://docs.openlinksw.com/virtuoso/rdfperfloading/
http://docs.openlinksw.com/virtuoso/perfdiag/

[MikiDi]

For reference: this small r-script is the only "prior art" that I could find out there wrt "autoconfiguring" Virtuoso .