Use relative imports in inotify.server.

Fixes an import failure I was getting under hgtk and hgweb:
*** failed to import extension inotify: 'module' object has no attribute 'inotify'

hgext/inotify/server.py

@@ -12,8 +12,8 b' import common'
 import errno, os, select, socket, stat, struct, sys, time
 
 try:
-    import hgext.inotify.linux as inotify
-    from hgext.inotify.linux import watcher
+    import linux as inotify
+    from linux import watcher
 except ImportError:
     print >> sys.stderr, '*** native support is required for this extension'
     raise