Create error handler Class

[beumerr]

The error class should be located in: root/admin/inc/QC_error

Study this page to design error hierarchies.

Attributes used to create error:

• function where error happens.
• message of what went wrong.
  error version control will be a future feature

Class attributes:
public $errors = [];

Class methods:

• usage_error - Call this function when used the wrong way
• system_error - Call this function when system has error
• draw_error - Display all errors

QC_panel.php

• Add draw_error hook underneath tag