python-matplotlib: add dateutil & pytz to DEPENDS/RDEPENDS

python-matplotlib is currently providing its own dateutil and pytz
Add dateutil and pytz as DEPENDS/RDEPENDS.
Patch setupext.py to no longer provide its own dateutil and pytz.
Remove python-matplotlib from blacklist.

Signed-off-by: Tim Orling <TicoTimo@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>