Done.

Sure, the LAMA preprocessor directories can be removed.

The LAMA trunk preprocessor has been merged into the trunk. As of r3294, we only
need the trunk preprocessor any more. LAMA's is identical apart from:

 * some additional copyright notices in LAMA's code that we won't retain
 * some small bug fixes (about dominance pruning in DTGs) only present in trunk
 * some comments only present in trunk

Also, as of r3299, all branches now read the new preprocessor format with action
costs, although some of them still ignore the action costs.

Silvia, are you OK with me removing the three LAMA preprocessor directories?

Then we'd be done merging the preprocessors.

As of r3280, only the following four preprocessors are left:

# find trunk branches -type d | grep '/preprocess$' | grep -v '/temporal' | grep
-v '/ext/'
trunk/downward/preprocess
branches/lama/trunk/downward/preprocess
branches/lama/branches/experimental/downward/preprocess
branches/lama/branches/lama-integration/downward/preprocess

The trunk preprocessor reads "Fast-Downward style" translator output (without
action costs) and writes "Fast-Downward style" preprocessor output.

The lama/trunk preprocessor reads "LAMA style" translator output (with action
costs) and writes "LAMA style" preprocessor output. The
lama/branches/experimental preprocessor is identical to this.

The lama/branches/lama-integration preprocessor reads "LAMA style" translator
output (with action costs) and writes "Fast-Downward style" preprocessor output,
so can be used to bridge the two worlds. It differs from lama/trunk in only four
lines of code.

Merging trunk and lama/trunk looks fairly trivial:
* Copy the few lines of code that deal with action costs from LAMA's code
  into the trunk.
* Deal with LAMA's output-format.txt, e.g. merging it with the documentation
  in trunk/downward/dist.

We need to merge the preprocessors from the various branches of the code, namely:

 * everything
 * lama/trunk
 * any others that are different from everything