renamed some db tables

you can now name your account as you want (yes, even version, default,
etc)

please delete your local db file
WIP: started refactoring the whole project

Everything should be working atm.

Some configuration keywords have been renamed:

verify -> ssl_verify
passwd -> password
type -> server_type

please update your config accordingly.

Also don't forget to delete your local khal.db file.

Also write support is now alway enabled. If this is a deal breaker for
you, please let me know and I'll put it back in.
bugfix: uploading modified events

forgot a hasattr
updated README