[2.0] More refactorings in Annotations parser and DQL parser. Now they only use constants instead of string processment

[2.0] Removed AssociationMappings from ResultSetMapping  for improved caching. Fixed caching issue with reflection classes and properties. Reimplemented and leaned up broken identifier quoting. Added support for named (native) queries. Fixed small hydration memory leak.

[2.0] Added more missing docblocks. Implemented a double-inclusion listener prevention in EventManager

[2.0] New Annotation API work: Simplifications, changed namespace separator to match the one of PHP, adjusted Lexer to swallow any * characters outside of a string value to be more forgiving when it comes to formatting.

[2.0] Moved cache drivers to Common package. Added new annotation parser implementation to Common package. AnnotationDriver in ORM not yet migrated.