Adding support for various notifications

* Adding new SQL upgrade for notifications
* Added support for per user notification settings
* Added account_id to notifications table
* Added new notification_settings table
* Added new account page: notifications

Addresses #144
Adding new notification system for new blocks

* Modified findblocks cron
* Modified notifications cron for new structure
* Improved notification class
* Added new template for new_block type
* Moved idle_worker type template
* Added new_block type to notification settings
wrong method call
Adding notification on automatic payout

* Added new mail template
* Added notification code to auto_payout cron
Added manual payout notification

* Added mail template for manual payouts
* Added code to account page to notify via mail on payout
* Added new option to notification setting template

Adds another feature to #144
wrong syntax in upgrade SQL
Updated SQL Files

* Updated upgrade SQL
* Added full new structure
Fixing issue with notification cron

* Updated getAllActive to search by type
removed commented section to re-enable auto-payout
adding full notification SQL for regular installations
Merge pull request #151 from TheSerapher/issue-144

Issue 144 : Add notification handler and settings