add /api/wms/1/wms?DATA_URL support
support addressing of files within zip via <url to zip>#<path within zip>
add a few docstrings
Merge branch 'develop' into feature/wms

* develop:
  update mapserver and enable wms/wfs client support
back to development
Merge branch 'develop' into feature/wms

* develop:
  back to development
  prepare release 1.5.4-rc1
add occurrence / absence csv support to wms endpoint
almays add default styles for occurrence and absence layers
prepare release 1.5.5