Add support for multipart body and fix issues

Hi Loïc,

Please help to review and merge this change set, thank you.
Changes:
1. Add support for specify none-body by set name=”null”
2. Fix a tiny issue of RestApiMethodDoc
3. Update index.jsp to modify color for PATCH tag
4. Update index.jsp to make the consume radio check first value by default
5.  Update index.jsp to add support for multipart body

Thanks,
Aiqin