Allows profile file to work on pathmunge-less systems.

Will check for pathmunge's existence and use it, or fallback to
prepending to the path.
Reduce size of profile.d-usrblackbox.sh to below 132 bytes.
Add test framework to make sure we don't break bash or sh.
Merge branch 'christophebiocca-fix-pathmunge'
Rewrite profile.d-usrblackbox.sh to only use BASH built-ins; retain file size <132 so that it is an "inline" file.
Eliminate "mungepath". Improve performance and assure script will not touch disk.