remove create_NEB from the repo

it was made obsolete by NEBDriver
start to add a CMakeLists.txt that can build the cython .so files
it works with a library now
add potentials/_pele.so to CMake build
add a cmake function to build the library automatically
add file to setup cython libraries with cmake
add -j flag to setup_with_cmake.py

This gets passed to cmake to enable parallel build.  It does not show up
the the help messge yet
the include paths are now automatically passed to cmake
Merge pull request #83 from js850/cmake_build

add an alternate setup file which builds the cxx extensions entirely with cmake
Merge pull request #82 from js850/remove_create_NEB

remove create_NEB from the repo
small updates to cython compilation
get the cmake build to work with OSX
remove default pbc use in cell lists
replicate some tests for cartesian cell lists, fix box size for test
add cartesian energy test, add corresponding inverse power
replicate hswca test
replicate lattice spacing tests
replicate applicable part of test
replicate more tests, hswca, 2d, frozen
add hswca cell lists frozen, replicate cpp tests