allow out-of-band saml signature verification

See merge request !58

Support for saml redirect bindings, where the signature is passed as
additional get parameters.

Unsigned requests

See merge request !57

Over quota tracking

See merge request !56

Introduce a flag for mailboxes that indicate whether this mailbox
is over quota or not.

The flag can be toggled through a dedicated endpoint that will be
triggered through dovecot.
Include current quota status in mailbox info and especially when
asking for a mailbox, so message delivery can be deferred at the
edge.

See https://doc.dovecot.org/configuration_manual/quota/ for background.

authentication convenience

See merge request !54

rename methods - https://rubyinrails.com/2019/04/09/rails-6-1-activerecord-deprecates-update-attributes-methods/

db maintenance - update schema & drop migrations + script to update schema from tests db

See merge request !48

update gems

See merge request !53

app pw admin access

See merge request !55

for admin show app pw and allow revocation

We have a mechanism where we allow logins only with the second factor if
the last login was very recent (maybe this is not a good idea anyway).
But for most people the totp is more annoying to get than the password.
So let's use the reissue mechanism only with webauthn.

fix an issue when trying to create a forward for an alias

See merge request !51

fix #21 - update gems

Closes #21

See merge request !49

too keep the db consisten

We used to convert back and forth between urlencoded and "standard"
base64. The webauthn standard wants urlencoded base64 and the webauthn
gem can now automatically deal with the conversion where needed.
Therefore let's switch to that everywhere. Since we use the
credential_id as the index for the database, we also need to convert
these keys.

set default quota to 30

See merge request !50

Script for importing bank statements

See merge request !46

* open api endpoints for creating and querying transactions
* allow creation of user transactions for other users
* remove deprecated bill import script

Reads a postfinance XML from stdin or file and references payments with
open reference numbers.