Fix for run argument with spaces in path

The first argument of "run" ends up being passed to the Perl built-in
"exec".  If the command has no arguments, then exec is only given a
single argument, which is then possibly subject to shell interpretation,
which can break if the value contains spaces and other shell special
characters.

Therefore, use the workaround described in the perlfunc man page of
using an indirect object so that even a single-element argument list is
not passed through the shell.

Fixes RT 97926
Merge pull request #7 from petere/fix-command-with-space

Fix for run argument with spaces in path