We decoded the wrong option here before.

It seems some update of the adLDAP library made a crucial function
protected, thus breaking the authad plugin.

This just makes the function public again, which should fix the
immeadiate problem. A proper fix would need to do #1553 as well

See https://github.com/splitbrain/dokuwiki/issues/1535#issuecomment-227039700

Otherwise you have to reapply the filtering every time you updated one
plugin.

See #1551

Changed the values recognized by the general config parser.
If value in config is a boolean it is recognized as boolean, not if it
is a string.

Fixes #718

This adds the possibility to define file with protected users in the
config cascade to be used with the plain auth mechanism.

This makes it possible for farms to have way to inherit Farmer users in
animals.