LILY-300: restore/delete emailaccount after auth problem
LILY-300: complete refactor of:

- IMAPClient raises connection error if connection fails on init
- If no client is set on IMAPClient, login returns False
- No more session storage of email_auth_update
- Correct (active)emailaccounts are used in tasks
- Util functions for checking imap/smtp credentials
Merge branch 'feature/change-email-password-300' into develop
LILY-361: historylist whatsapp style
Merge branch 'hotfix/0.2.9' into develop
Hotfix: Email Compose template now loads wysihtml5 css
Merge branch 'hotfix/0.2.10' into develop
Hotfix: Email Compose template now loads wysihtml5 css properly
Merge branch 'hotfix/0.2.11' into develop
Fix circular import
Merge branch 'release/0.2.12'

Conflicts:
	lily/static/lily/scripts/inbox.js