Move internal implementation from Zend\Code to PHP-Parser

[Ocramius]

Moving to PHP-Parser will allow inlining of parent class code, therefore reducing linear overhead and allowing more performance optimizations.

[Ocramius]

Clearing milestone: this won't happen for a while, since PHP-Parser is far from our needs right now

[robfrawley]

👍 omg, yes - please! Need help? ;-)

[malukenho]

@robfrawley fell free to send PRs 😄

[Ocramius]

I'm not sure if this is interesting/viable anymore.

There is no clear advantage in using PHP-Parser unless very obvious automated optimizations can be applied.

[Ocramius]

Note: can easily be fixed if Roave/BetterReflection#39 is carefully checked