Redesign of frontend, dashboard, and admin section. Created OpenCFP logo. General cleanup of templates

This is a complete face lift of the current UI. The site now provides ease of theming and clean UI/UX.
Remove now unused classes.

Migrations moved to phinx so migrator is no longer needed. Spot2 has taken
over as the ORM, so model classes are no longer necessary.
Speaker entity was deprecated in favor of user entity.
Fix incorrect class name for group and setup proper relationship
Remove unused relationship and fields from entities
Needless transform of data was simplified to a single entity return
Changing admin group name to match migration casing
Logged in users that attempt to access registration page are no longer logged out, but redirected to the dashboard
Moved schema seed file into first migration from SQL file.

By doing this it allows us to avoid MySQL specific table creation and allows
phinx to change queries as needed (i.e. if someone wanted to use sqlite for local dev)
Add SVG Injector to allow the use and modification of svg images