Add support to open/close information window

[pmacMaps]

I've added support to open/close the information window. I put the custom CSS and JS in seperate files. I did make some changes to the index.html.

You can take this or leave it. But I think it does improve the project.

If you like the concept, here are some enhancements:

• use a pretty open/close icon
• add a transition for the left property changes