[FIX] M2M Field
[COS] Constraints and sql constraints multi-line, some small usability fixes
[FIX] Onchange method signature and return value
Community standards for import and class inheritance, remove model description and call to class at the bottom as it's not required
Remove readonly as it's hardly ever used and not the hardest thing to remember; change char field string default to Name as it's the most commonly used one