Doc: Fix most of the documentation warnings

- adding missing index files to \depends
- fix warning: Can't link to 'The QtWebKit Bridge'

Change-Id: I60665627f1aadbf7bd8a20ddda7d22db9ad694dc
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>