Import the QtWebKit documentation

This places the documentation in separates .qdoc files with the original
license header preserved. We don't want to contaminate our implementation yet
just for the documentation, so keep it separate for now.

New documentation that isn't attached to the QtWebKit LGPL license should go
inline in the code as usual.

Change-Id: I113a9ad2b826ed7cea053be065f201b637070d28
Reviewed-by: Andras Becsi <andras.becsi@digia.com>