PageLoader updates:
 - Add support for Class-level refinement annotations.
 - Add caching of reflected info used to construct POs.
PageLoader updates:
 - Add support for Class-level refinement annotations.
 - Add caching of reflected info used to construct POs.
Merge branch 'class_annotations' of https://github.com/DrMarcII/dart-sync-webdriver into class_annotations
Move classInfoCache to _ClassInfo.
Fix classinfo caching.
Add TODOs to reenable support for private constructors/setters if/when mirrors
get fixed.
Merge pull request #11 from DrMarcII/class_annotations

PageLoader Updates