Some significant enhancements

Hi,
I have made some engancements that I hope will user to make his work easier. There are:

1. Now user can take content not only from text editor but from Internet too. That is he or she can indicate URL and content will be taken from this url.

2. User now can indicate a some label or identifier for every node. And then insert it into the link where the doc is opening from. When user click this link the given node will be opened not default one (first).

3. User can edit the title of window with docs.

4. Some refactoring have been made. Particularly, I am gradually moving from prototype library to ajax.net.

5. I have wrote some texts for site.

Tome spent (for these days): 11 hours