Make ircd.storage keep a cache and write back every 5 sec

This prevents performance problems due to pickling and unpickling a thing thousands of times
Actually finish addListMode and add a necessary parameter
Merge pull request #9 from ekimekim/shelve-cache

Make ircd.storage keep a cache and write back every 5 sec
Merge pull request #10 from ekimekim/dev/0.3

rfc/message: clean up a no-longer-used import
Fix function parameter names in MessageCommands module
Add LocalUsers to the userNicks dict
Sync metadata across servers