Refactor ClassMetadataFactory logic to cache Entity ClassMetadata classes and load them from Filesystem.

[guilhermeblanco]

[Ocramius]

@guilhermeblanco if possible, just abstract it behind a tiny interface, which would later allow for code signing (important to prevent tampering with files in some production systems).

EDIT: sorry, didn't mean to close. Tabbed to the wrong button :-)

[guilhermeblanco]

@Ocramius I'm taking the same approach as ProxyFactory is doing today. =P