PHP Coding Standards

I used the PHP Coding Standards Fixer tool (php-cs-fixer).
Fixed inconsistant indentations (4 spaces).
PHP Coding Standards #2
CS fixed

Indentation fixed
Case for null, true and false fixed
oauth2-php cs fixes
CS fixed
Fixed missing@return
Fixed typo
camelCase
Align
full list of changes below:
- cleaned up OAuth2
- cleaned up OAuth2AuthenticateException
- cleaned up OAuth2RedirectException
- cleaned up OAuth2ServerException
- added missing @params
- added missing @param types
- added missing comment blocks