Merged.

 * I added some small error checking to the plan script.
 * I made some small changes to the make_ipc_submission script:
   * All sanity tests are enabled now by default (except for the 2nd planner
     test, which requires axiom support in the config), but can be disabled
     easily with a variable at the top of the script.
   * -m32 in the Makefiles is now replace with -m64 upon packaging.
   * The LP library is removed. (Looks like we're not going to use it, and
     if we wanted to include it, we'd have to be more careful with the license.)

Done and pushed into my repository.
Reminder: we still need to switch from -m32 to -m64 at some point (or maybe do 
this automatically)

We should create a script that exports only the planner, and create build/plan 
scripts, as IPC rules specify.
(I am already working on this, this is just to have a branch name)