Doxygen warnings corrected

* Doxygen spits out a lot of warnings about not being able to find
  match function signatures, etc. This is because in some headers we
  have a using namespace statement, in others it gets confused between
  ::Window and Window (!).

* Wrong use of tags:
  + Lots of @seealso - should be @see
  + Wrong usage of @overload - corrected with the right function
    signature
  + HTML tags that doxygen doesn't recognize removed

Conflicts:
	include/vcl/toolbox.hxx

Change-Id: I687f45e426280d411ef3cb6d8d5993a829f2f324
Reviewed-on: https://gerrit.libreoffice.org/7725
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>