temporarily remove submodules.
edited makefile to be less destructive and more helpful.
synced graph_reference back into project.
synced mplexporter, new file from update included.
fixed reference to new submodule locations in repo.
running make should be more self-explanatory. run `$make` in root dir.
added a setup script in the makefile for initializing submodules.
setup_subs target now does *everything* you need to setup submodules.
Added instructions on setting up submodules locally.
updated readme to include a note about contributing to the repo.
Merge pull request #42 from plotly/refactor-submodules

Refactor submodules