Fixed the distributed singlebox example.
Modified the MPI and MPI-LPEL configs to work with openmpi on OS X.
Fixed the language interface used by the distributed singlebox example.
Merged older distributed singlebox fix.
Added OSX dSYM util folders and test output to the .hgignore file.
Improved error reporting in C4SNet.
Added test config that runs valgrind on all pthread tests.
More flexible instantiation, using an AST of the network.

Changed RTS to generate an AST structure upon start, rather than instantiating
the network directly. This gives the ability to instantiate only parts of the
network.
Introduced a new tree based notion of location vector.
Added proper freeing code to the info structure.
Added proper unique identification of nested dynamic network instances.

New naming function that uses the AST based location vector and the snet_id_t
introduced in this patch to compute the name of an entity.
Removed old locvec implementation and replaced the functionality with a new one
based the new AST and id vectors introduced in earlier patches.
Merge with Merijn tree (-locvec +ast)