bin/ scripts to follow symlinks

Since many applications now symlink one, or more, times into multiple directories these scripts needed updated to accurately follow said symlinks. Previously, if symlinks were present, the script would fail to find all of the .jar files in the library because it would only find the immediate path it was installed in. For example, if we symlinked rexster.sh to /usr/local/bin/rexster and attempted to call it, the script would only look in /usr/local/lib/ for its jar files which would fail to launch.

This is similar to the patch for the rexster-console script that was submitted a while back (tinkerpop/rexster#353) which details the discussion and problem.

The impetus for this patch is to get it fixed and in the upstream version for the next release build such that the homebrew formula to install titan (homebrew/homebrew#30107) can be accepted for the wider community.

Let me know if there are any issues or concerns!