start in on dart codegen
dart codegen updates
:private for classes changes name to private
added 'generated' sections
support for dart enums
added public constants to lib
id now has shout convention
parser for altova model
start for support for dart codegen
parser for XMI (at least altova saved XMI)
json work
fix json ctor. fix member assignment to prefix this. if required
fixed json_in and json_out used by json templates
added member dup_init