Save more info in result files to help reproducing them

[avarga]

Saving more information in result files sca/vec could improve the chance that the simulation can be re-run to produce the same results. The following items could be saved as run attributes (perhaps only if enabled by some config option):

• working directory
• NED path
• command line
• OMNeT++ version, platform, build info (see opp_run_dbg -v output)
• if working directory is under git, the current branch name and commit hash (?)