* Working on subscriptions
* Implement return type in models
* Subscription implementation
* Improvements to handling importation of large accountS
* Loggin imports
* Activate collector
* Improve memory usage of import script
* Appen Tags into emails - fix companygatewaytransformer
* Improve notification performance
* Cascade deletes
* Fixes for company deletes
* Fixes for formatting
* todos for company
* Set currency id on payment
* Minor fixes for payment controller
* Client and System Notifications
* Fix for group settings currency not applying correctly.
* Split head out of design in order to reuse headers and footers
* export the designs
* Fixes for pdf_variables
* Performance improvements for seeding
* Differentiating between system notification and user notifications
* Remove hard coded webhook url
* Working on system and user notifications
* notifications
* Set the currency on client if blank
* Refactor for inserting invoice defaults
* Refactor Default Invoice/Quote/Credit objects
* working on credits
* Implement mark_sent for quotes and credits