update pip packages, install pyPdf and reportlab via pip

* pip itself is updated
* moved python libs without problematic external deps to pip install
removed ldap from pip install, pypdf moved back to apt

* ldap is installed by apt and was installed by pip again
* pypdf is fetched from untrusted source by pip, better use apt
README changes, db pass fixes

* db pass contains only letters and numbers now
    (other chars are problematic in some cases)

* db pass is read again in mediatum =>
    can run independently from db role if password file is present
* improved README a bit
* version bump for ansible to 1.6
added basic supervisor help
fixed supervisord.conf

* http socket was configured twice...
chown for supervisor socket was missing