Temporary PR for testing 773 and 793

fixture/flat/.zarray

@@ -0,0 +1,22 @@
+{
+    "chunks": [
+        2,
+        2
+    ],
+    "compressor": {
+        "blocksize": 0,
+        "clevel": 5,
+        "cname": "lz4",
+        "id": "blosc",
+        "shuffle": 1
+    },
+    "dtype": "<i8",
+    "fill_value": 0,
+    "filters": null,
+    "order": "C",
+    "shape": [
+        2,
+        2
+    ],
+    "zarr_format": 2
+}

fixture/nested/.zarray

@@ -0,0 +1,23 @@
+{
+    "chunks": [
+        2,
+        2
+    ],
+    "compressor": {
+        "blocksize": 0,
+        "clevel": 5,
+        "cname": "lz4",
+        "id": "blosc",
+        "shuffle": 1
+    },
+    "dimension_separator": "/",
+    "dtype": "<i8",
+    "fill_value": 0,
+    "filters": null,
+    "order": "C",
+    "shape": [
+        2,
+        2
+    ],
+    "zarr_format": 2
+}

zarr/__init__.py

@@ -9,7 +9,7 @@
                            zeros_like)
 from zarr.errors import CopyError, MetadataError
 from zarr.hierarchy import Group, group, open_group
-from zarr.n5 import N5Store
+from zarr.n5 import N5Store, N5FSStore
 from zarr.storage import (ABSStore, DBMStore, DictStore, DirectoryStore,
                           LMDBStore, LRUStoreCache, MemoryStore, MongoDBStore,
                           NestedDirectoryStore, RedisStore, SQLiteStore,

zarr/core.py

@@ -1952,7 +1952,7 @@ def _process_for_setitem(self, ckey, chunk_selection, value, fields=None):
         return self._encode_chunk(chunk)
 
     def _chunk_key(self, chunk_coords):
-        return self._key_prefix + '.'.join(map(str, chunk_coords))
+        return self._key_prefix + self._dimension_separator.join(map(str, chunk_coords))
 
     def _decode_chunk(self, cdata, start=None, nitems=None, expected_shape=None):
         # decompress