Feature Steal The Sky

you can now use MarshalWithVariable to Marshal the golang struct which will takeover the default json marshaling procedure with variable syntax format. see the README.md ;-)

plugin and meta extension on AST

add extension on AST node: plugin and meta data.

rework the processing of go's json string, slice byte conversion using plugin and meta data.

support golang json marshal unmarshal api

most of the json.Marshal and Unmarshal scenarios are supported, if you find one that is missing feel free to open a ticket.

1. remove the dependency of json.Marshal/json.Unmarshal, use the marshaler and unmarshaler from our own. (cross check with json.Marshal and Unmarshal in unit test pass)
2. string option support for json tag, marshal & unmarshal
3. omit empty tag support
4. string option tag support
5. cyclic access detection during marshaling

support json.Unmarshaler interface

1. support json.Unmarshaler interface
2. fix bug #3

support golang json field tag

Add field tag support

support unmarshal into go's struct

add support to unmarshal the template string into go's struct, with variable replacement.