Lots of bugfixes. Removed temporary files.

+ Account is now EmailAccount
+ EmailAccount encapsulates things better
+ AccountFrame now can make new accounts
+ MainWindow asks for new account if none found
+ MainWindow gets new mail from INBOX and puts it in account folder
+ Message list is now dedicated class and is working
+ Mailbox folder list is now dedicated class and is working
+ Added new factory for inbox classes
- Removed cruft from main startup file