ASClassWizard: improved class name errors + validation for Haxe

$ is not valid in Haxe class names
Haxe class names must start with an uppercase letter
ASClassWizard:  "final" support for Haxe
ASClassWizard: move $(ClassMetadata) to next line
Merge pull request #513 from Gama11/HaxeClassWizard

Improved Haxe compatibility for ASClassWizard