make cls did not generate a correct pdf

make cls was just calling pdflatex once and thus, not generating the reference
 correctly. Since the .cls and the .pdf are extracted from the same source,
make cls can be removed and we can use make pdf instead.
\bookmarksetup{startatroot} is alread inside \postextual.

Nobody is going to use the conclusion chapter like that.
references now showing on the toc.

The code from abntex almost fits our needs. It formats the list of references
correctly, but the toc entry is not in upper case. The added code disables
the default writing to the toc and creates a new entry in uppercase. There's
also the need to clear the prebibhook to prevent the pre-abstract bibliographies
from appearing in the toc.