Allow custom Quoter to be injected into CompositeHandler

New internal API, and remove security risks

Display private properties from parent classes

Second MAJOR version

Create first MAJOR version

Respect\Validation has been using this library since the end of 2017,
and there haven't been any changes or reported bugs, and Packagist
registers almost 5.2M installs (probably because of Respect\Validation).

I think it's safe to assume that this library is stable enough and
deserves a MAJOR version release.

Many fixes and removal of PhpParsableStringifier

First release