Bug fix.
P4#run was not handling arrays passed as arguments -
which is what P4#method_missing does. It was just calling to_s
on all its args, and Array#to_s joins all the elements of the
array so if you passed more than one argument to a run_xxx method,
it was joining them together.
This change involves flattening an array of Ruby objects (some of
which could be arrays themselves) into a single C++ array before
executing the command.