GEOS-6086 remove WfsDispatcher from describelayer

and all other places in the code base
(cherry picked from commit 248259585f5fb8de5efe5d751da4908186d52c6d)
Merge pull request #360 from ischneider/GEOS-6086-2.3.x

GEOS-6086 remove WfsDispatcher from describelayer