Put the doxygen dependency on the quickbook file, rather than boostbook.

Because when building the main documentation, the docbook target isn't
being triggered, which is breaking the build. Hopefully this will fix
it.
Merge pull request #2 from danieljames/doc-build-fix

Put the doxygen dependency on the quickbook file, rather than boostbook.
Fix the documentation redirect location.
Merge pull request #3 from danieljames/redirect-fix

Redirect fix