Allow publish to Blogger Page

[wiibaa]

As you suggested in #268, here are the addition to publish a document as a page on Blogger.
I documented a few shortcoming of the current API in the modal form as I found them by testing.
Please have a look to verify I was clear enough and if it can be merged as is.

Also did you already need to discuss such limitations with Google developers?
If yes did you use the google group
https://groups.google.com/forum/#!forum/bloggerdev
or the issue tracker
https://code.google.com/p/gdata-issues/
and how was the feedback?

[benweet]

Well done. Do you have a preferred username and a website url to add in the about dialog?

[wiibaa]

Thanks you.
Simply my github user name is best to identify me. My fullname (Philippe Weber) is a little too common. No URL.