Revamp events and refactor/reformat code

[kartik-v]

• All event traits are removed and base events classes are used instead (thereby avoid declaring public properties in traits for classes)
• Added unavailable comyii\user\events\admin\CreateEvent
• Revamped clients and included ClientTrait and base Client class
• Renamed client classes to end with Auth for consistency
• Move all social authentication classes and methods to social folder and namespace
• Moved EmailException class to components folder
• Revamped PHP Documentation and edited various classes
• Various code formatting updates

[kartik-v]

@derekisbusy ... FYI... I am incorporating updates to the repo via this issue.

[derekisbusy]

Okay, I just pushed what I have for now. Also I moved the clients to comyii\user\authclient\clients to match that of the yii\authclient\clients structure.