Bump copyright
Add SOGoCredentialsFile

New class to read credentials files as used by sogo-tool and sogo-ealarm-notify
Add SOGoStaticAuthenticator

New authenticator that is not linked to a SOGoUser.
Will be used for SMTP AUTH by sogo-elalarm-notify.
Special case for auth with SOGoStaticAuthenticator
Use SOGoCredentialsFile to avoid duplicated code
Support using SMTP AUTH creds for email alarms

Credentials must be supplied using '-p /path/to/credsFile'.
The credentials file should contain a single line with the format 'user:pass'

While there, add a usage message
Merge branch 'fix/email-notif-auth'