Rename VSI plugin prefix

Resolves #1369

Author: sgillies

CHANGES.txt

@@ -27,6 +27,8 @@ New features:
 
 Bug fixes:
 
+- Fiona's python opener VSI plugin prefix has been changed to "vsifiopener" to
+  not conflict with Rasterio (#1368).
 - Add a 16-bit integer type "int16" based on OGR's OSFTInt16 integer sub-type
   (#1358).
 - Allow a GeoJSON collection's layer name to be set on opening in write mode

fiona/_vsiopener.pyx

@@ -19,7 +19,7 @@ log = logging.getLogger(__name__)
 
 # Prefix for all in-memory paths used by GDAL's VSI system
 # Except for errors and log messages this shouldn't really be seen by the user
-cdef str PREFIX = "/vsipyopener/"
+cdef str PREFIX = "/vsifiopener/"
 cdef bytes PREFIX_BYTES = PREFIX.encode("utf-8")
 
 # This is global state for the Python filesystem plugin. It currently only