Add Docs and Tests

Add documentation and unit tests for the DisallowShortOpenTag sniff.
Update ScopeIndent Sniff

Fix the bug where a top-level structure would have the incorrect indentation calculated, by increasing the indentation calculated by one indentation's worth.
Update ScopeIndent Sniff

Add a check for the class that it extends.
Update ScopeIndent Sniff

Update the names of the class in the DocComments.
Update DisallowShortOpenTag Sniff

Update the name of the class in the DocComment.
Update ClassDeclaration Sniff

Override the register() method to include traits, as well as classes and interfaces.
Update ClassDeclaration Sniff

Override the process() method to implement our own rules.
Code Formatting
Create NamespaceDeclaration Sniff

Create our own sniff to override the one with the same name in PSR2.