cherry-pick changes to release branch

2cca587 (Wolfgang Bangerth, 11 minutes ago)
   Fix missing instantiations.

664267f (Matthias Maier, 13 hours ago)
   Update documentation of DEAL_II_WITH_* lists, and testsuite configuration

37fae4e (Matthias Maier, 13 hours ago)
   remove obsolete functionparser definitions

0ee5103 (Matthias Maier, 13 hours ago)
   Add an additional hint for opencascade