Define version constants etc in __init__.py

Move central constant definitions into __init__.py.  This does away
with version.py which contained nothing else and __init__.py is where
things like __VERSION__ are usually defined.

This commit also changes code to use offlineimap.__version__ rather
than offlineimap.version.__version__ as was before. Cleaned up some
duplicate or unneeded imports while touching those, formatting import
statements per PEP8 (one import per row).

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

offlineimap/ui/UIBase.py

@@ -61,8 +61,8 @@ class UIBase:
     def setlogfd(s, logfd):
         s.logfile = logfd
         logfd.write("This is %s %s\n" % \
-                    (offlineimap.version.productname,
-                     offlineimap.version.versionstr))
+                    (offlineimap.__productname__,
+                     offlineimap.__version__))
         logfd.write("Python: %s\n" % sys.version)
         logfd.write("Platform: %s\n" % sys.platform)
         logfd.write("Args: %s\n" % sys.argv)
@@ -174,7 +174,7 @@ class UIBase:
         where the UI should do its setup -- TK, for instance, would
         create the application window here."""
         if s.verbose >= 0:
-            s._msg(offlineimap.version.banner)
+            s._msg(offlineimap.banner)
 
     def connecting(s, hostname, port):
         if s.verbose < 0: