This should be fixed now.

> "downward" should always be the run

=> "downward" should always be run

"downward" should always be the run, but it can itself run all of dispatch,
downward-1, downward-2 and downward-4, so these four must be available, too, in
the same directory as "downward". "downward" may be renamed freely, but the
other ones may not, or downward won't find them. So I think it makes sense to
introduce a subdirectory where everything can live under its usual name.

At the moment the scripts take the first suitable planner found in the 
search dir. How do you want to specify which planner is supposed to be 
used (downward-1 vs. downward-2 ...)? What is the dispatch executable?

(Classifying this as "bug" since the scripts currently don't work, although it's
not their fault.)

The new_scripts don't work in the IPC repo since it will only copy the
"downward" script, but not the "dispatch" script and "downward-1", "downward-2",
"downward-4" executables, which are also needed. Also, the mechanism of
appending -REVISION to everything won't work since then downward wouldn't find
the dispatch script and downward-{1,2,4} executables anymore.

Suggested fix:
Instead of this layout:

exp-dir/search-REV1
       /search-REV2
       /runs-00001-00100/00001/...
                        /00002/...

use this:

exp-dir/code-REV1/downward
                 /dispatch
                 /downward-1
                 /downward-2
                 /downward-4
       /code-REV2/downward
                 /dispatch
                 /downward-1
                 /downward-2
                 /downward-4
       /runs-00001-00100/00001/...
                        /00002/...

etc.

In the case of --preprocess or --complete experiments, the preprocessor and
translator should also live under code-REV.