Added disambiguation for all variables (I put braces on them).  Fixed a typo where a brace and dollar sign were backward.  Changed HIERA__CMD to HIERA_CMD.  Made HIERA_CMD not read-only because in the user-name case it is assigned a new command string.
Added disambiguation for all variables (I put braces on them).  Fixed a typo where a brace and dollar sign were backward.  Changed HIERA__CMD to HIERA_CMD.  Made HIERA_CMD not read-only because in the user-name case it is assigned a new command string.

llowder/Zwiebelschaler