update README and other docs to call the project Apache Answer instead of Answer

[pjfanning]

Maybe not needed everywhere but the first reference on a page or section should probably refer to Apache Answer instead of Answer.

You have the Incubator footer on your web site pages but you might want to consider mentioning Incubation status of the project in the main body of your main page.

[fenbox]

Thanks for the feedback, the website has been updated.