Adding csscolorparser and support for css color selection.
Add atom property predicate generators.

Add helper functions to generate property predicates, used in functional
atom selection code. Updated getAtoms to accept atom lists or atom index
lists and return only atoms, not undefs, if provided invalid input.
Updating glmol embed with reasonable default representation.
Update setup_js.py for initial support of ipython embedding.
Move changes under `embedding` into `src`.

Moving changes made for embedding back into `src` directory. Including
source versions of all library dependencies, `three.js` and
`csscolorparser.js`, and removing extraneous source scripts. Updating
viewer.html and example_embed.html to load source scripts.
Removing extraneous embedding directories.

IPython embedding support moved to separate project, `ipython_glmol`.