Add type="button" to all generated buttons!

This caused the weirdest bug ever with an item’s delete button becoming
the de facto submit button of a form. Holyshit.

src/collection.js

@@ -585,6 +585,7 @@ var _ = Mavo.Collection = $.Class({

			if (!button) {
				button = $.create("button", {
					type: "button",
					className: "mv-add",
					textContent: this.mavo._("add-item", this)
				});

src/mavo.js

@@ -646,6 +646,7 @@ var _ = self.Mavo = $.Class({
				this._("item-deleted", {name: phrase}),
				{
					tag: "button",
					type: "button",
					textContent: this._("undo"),
					events: {
						click: evt => {

src/ui.bar.js

@@ -64,6 +64,7 @@ var _ = Mavo.UI.Bar = $.Class({
			}
			else if (!this[id]) {
				this[id] = $.create("button", {
					type: "button",
					className: `mv-${id}`,
					textContent: this.mavo._(id)
				});

src/ui.itembar.js

@@ -23,10 +23,12 @@ var _ = Mavo.UI.Itembar = $.Class({
			var buttons = [
				{
					tag: "button",
					type: "button",
					title: this.mavo._("delete-item", this.item),
					className: "mv-delete"
				}, {
					tag: "button",
					type: "button",
					title: this.mavo._(`add-item-${this.collection.bottomUp? "after" : "before"}`, this.item),
					className: "mv-add"
				}
@@ -35,6 +37,7 @@ var _ = Mavo.UI.Itembar = $.Class({
			if (this.item instanceof Mavo.Group) {
				this.dragHandle = $.create({
					tag: "button",
					type: "button",
					title: this.mavo._("drag-to-reorder", this.item),
					className: "mv-drag-handle"
				});

src/ui.message.js

@@ -40,6 +40,7 @@ var _ = Mavo.UI.Message = $.Class({

		if (o.dismiss.button) {
			$.create("button", {
				type: "button",
				className: "mv-close mv-ui",
				textContent: "×",
				events: {