add mpi4py from March 2014
Add Linux Arch environment and host packages

* Revision of 5c238

Suggested-by: Jed Brown <jed@jedbrown.org>
Add Clawpack + Git Submodule test

Clawpack uses relative submodules, so it's a good test of our submodule
functionality.  This does not test the parallel aspects of Clawpack, but
this could be added by installing a PETSc installation.
Merge pull request #185 from hashdist/add_clawpack_test

Add Clawpack + Git Submodule test
Merge pull request #182 from hashdist/ahmadia/archlinux-patches

Add Linux Arch environment and host packages
Merge pull request #178 from hashdist/ahmadia/add_mpi4py

add mpi4py from March 2014
Add missing arch.yaml file
Merge pull request #187 from hashdist/add_arch

Add missing arch.yaml file
Make szip build in NoType mode, so that we work around the liblibszip bug.
Merge pull request #192 from robertmaynard/cmake_package

Make szip build in NoType mode, works around the liblibszip bug
Add Julia package
Clone submodules by hand
Use latest git version

Use submodules. Download things from the internet during the build for now.
Use prefix, no dependencies

Now it builds and installs properly