Move dbopen(), dbclose() to wendelin.lib.zodb

Factor out those routines to open a ZODB database to common place.

The reason for doing so is that we'll soon teach dbopen to automatically
recognize several protocols, e.g. neo:// and zeo:// and this way,
clients who use dbopen() could automatically access storages besides
FileStorage.

bigarray/tests/test_arrayzodb.py

@@ -16,8 +16,8 @@
 #
 # See COPYING file for full licensing terms.
 from wendelin.bigarray.array_zodb import ZBigArray
-from wendelin.bigfile.tests.common_zodb import dbopen, dbclose
 from wendelin.bigfile.tests.test_filezodb import kkey, cacheInfo
+from wendelin.lib.zodb import dbopen, dbclose
 from persistent import UPTODATE
 import transaction
 from numpy import dtype, uint8, all, array_equal

bigfile/tests/bench_1filezodb.py

@@ -4,7 +4,7 @@
 from wendelin.bigfile.file_zodb import ZBigFile
 from wendelin.lib.mem import memset
 from wendelin.lib.testing import Adler32, nulladler32_bysize, ffadler32_bysize
-from wendelin.bigfile.tests.common_zodb import dbopen, dbclose
+from wendelin.lib.zodb import dbopen, dbclose
 import transaction
 from tempfile import mkdtemp
 from shutil import rmtree

bigfile/tests/test_filezodb.py

@@ -16,8 +16,8 @@
 #
 # See COPYING file for full licensing terms.
 from wendelin.bigfile.file_zodb import LivePersistent, ZBigFile
-from wendelin.bigfile.tests.common_zodb import dbopen as z_dbopen, dbclose
 from wendelin.bigfile import ram_reclaim
+from wendelin.lib.zodb import dbopen as z_dbopen, dbclose
 from persistent import UPTODATE, GHOST
 import transaction
 from tempfile import mkdtemp

bigfile/tests/common_zodb.py → lib/zodb.py

-# Wendelin.bigfile | common bits for ZODB-related tests
+# Wendelin.bigfile | common ZODB-related helpers
 # Copyright (C) 2014-2015  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #