Change egg format to yaml

[lancepioch]

Work in progress, here's some of the current changes:

Optional:

• [ ] user_viewable - true
• [ ] user_editable - true
• [ ] description - ""
• [ ] rules - "" or []
• [ ] default_value - null or ""

Other:

• [ ] egg - whole thing backwards compatible with json because of superscript
• [ ] config - no longer json strings, just normal yaml/json
• [x] field_type - removed because of non usage, inferred from rules