Updating bin path management.

Updating bin path management to work with the new `dpp-msbayes` package
executable names. This entailed updating `get_tool_path_mapping`
function `MsBayesWorker` class.
Updating linux bin.

Updating executables in the linux bin directory. Executables now reflect
new names of `dpp-msbayes` package, and avoid having to maintain an
"old" and "new" subdirectory.

Executables were compiled statically on 64-bit Rocks cluster (kwyjibo).
Updating `setup.py`.

Removing call to `symlink_msbayes_requirements` function, because this
is no longer necessary. The new executable names of the `dpp-msbayes`
package now allows both the new and old implementation to coexist
without separate directories.
Updating mac bin.

Updating executables in the mac bin directory. Executables now reflect
new names of `dpp-msbayes` package, and avoid having to maintain an
"old" and "new" subdirectory.