v5.1.0

• Fix date handling when dealing with very low year numbers. (Thanks @jfly)
• For type="update" and type="method-update" forms, a formToModifier hook is called instead of formToDoc, and it's passed a Mongo modifier. For forms with no type attribute, both formToDoc and formToModifier are called. (You should provide one or both based on whether you use the doc, the modifier, or both in your onSubmit hook.)
• Array handling was changed in 5.0 to support additional use cases. However, this change also resulted in a MongoDB array handling quirk no longer being masked by AutoForm. Since this caused confusion for many people, array handling is now reverted back to pre-5.0 behavior. If your form needs to update specific array items as opposed to entire arrays, you can opt in to the proper array handling by putting setArrayItems=true on your autoForm or quickForm.
• For "method" and "method-update" type forms, before hooks will now run before validation, unless you've specified both a schema attribute and a collection attribute. In that case, validation against the form schema happens before the before hooks run, and validation against the collection schema happens after the before hooks run, before your method is called.
• Changes to avoid benign errors being thrown.
• Fix potential for infinite loops related to tracking field values.