MPI-Bash v1.1

This release represents a significant improvement to the way that MPI-Bash is built and deployed. Previously, in version 1.0, MPI-Bash was distributed as a set of patches to the Bash source code and was therefore tied to a specific version of Bash (Bash v4.3, to be exact). In version 1.1, MPI-Bash is built as a Bash plugin ("loadable builtin" in Bash terminology) and therefore enjoys some degree of forward and backward compatibility with Bash versions. It still requires the Bash source code to build, but only because few if any Linux distributions provide the Bash development header files. Finally. the MPI-Bash build process now uses the GNU Autotools for their features and robustness.