Run auto-format tool to match PSR rules
Modernize methods' names
Stop polluting global scope

In case we don't have getallheaders() function we should not add it; instead now we're using private method to resolve this.
Fix typo
Fix scope of methods and variables

Add new methods to access now private variables (all variables are now private).
We've introduced strict scoping policy; we're not using "protected" scope at this point.
Define local private field
Update composer configuration file
Drop closing PHP tag
Run auto-format code on composer configuration
Define ExceptionalData::$data private field

Additionally to have access to it we now have getData() public method.
Fix tests' methods scope
Fix white-spaces
Define private $data field
Use static:: instead of self::

Use static:: instead of self:: whenever static method is being invoked.
This is a first attempt to make PHP Exceptional extensible.
Unify return value
Move preparing POST data to separate method
Rename internally used variables
Fix type hinting
Update preaprePostData() method
Add Psr/Log requirement

This was done to allow standardized Exception logging upon socket error.