Fixed a spurious windows error due to Window's low-resolution clock.

src/ZODB/DemoStorage.test

@@ -5,6 +5,17 @@ DemoStorage demo (doctest)
 DemoStorages provide a way to provide incremental updates to an
 existing, base, storage without updating the storage.
 
+.. We need to mess with time to prevent spurious test failures on windows
+
+    >>> now = 1231019584.0
+    >>> def faux_time_time():
+    ...     global now
+    ...     now += .1
+    ...     return now
+    >>> import time
+    >>> real_time_time = time.time
+    >>> time.time = faux_time_time
+
 To see how this works, we'll start by creating a base storage and
 puting an object (in addition to the root object) in it:
 
@@ -73,7 +84,7 @@ Our lastTransaction reflects the lastTransaction of the changes:
     >>> storage.lastTransaction() == changes.lastTransaction()
     True
 
-Let's walk over some of the methods so ewe can see how we delegate to
+Let's walk over some of the methods so we can see how we delegate to
 the new underlying storages:
 
     >>> from ZODB.utils import p64, u64
@@ -378,3 +389,7 @@ DemoStorage keeps up with the issued OIDs to know when not to reissue them...
 We're done with the storage, so "unwrap" the underlying storage.
 
     >>> storage = storage.pop()
+
+.. restore time
+
+    >>> time.time = real_time_time