Opening Files

	Currently MolViewer only allows you to have one molecule loaded at a time. Opening a molecule will remove  whatever molecule you are currently viewing. Most of the code is in place for support of multiple molecules, but there were other things I wanted to impliment first.

	Three file formats are currently supported (see the next section). I will add more on request. If you have a format you'd like to see MolViewer support, please send me a description, and I'll impliment it. It takes almost no time to do...