added direct __isset() so mustache can use these models
rewrote Model::flatData() to be simplere and support more
added Model::fieldNotNull()
fixed Collection::at() to use Model's stored _type if it is set
fixed reference saving and collection flattening in Model
added 'default' to field defs
relatives now preserve keys when saved (this might break Collection's data for now as it should be keyed by id)
new validator: schemaValidatorToList (to save unordered lists for mustache)
added SchemaValidatorToBool
Merge /var/www/maui into V0.1
Collection - fixed add() and added append()
Model - fixed getField() for multi fields when only originaldata is set
Schema - changed '@extends' to '@@extends' so '@field' extension can be specified
Validators - added own value resolution to other fields of the model