v3.1.1

• dom_builder: ^3.2.0: a false boolean attribute (selected="false", hidden="false"...) no longer turns it on;
  every selected="false" option was selected, so a <select> (as an app's language menu) showed its last option.
  Also resource_portable: ^3.1.4 and build_web_compilers: ^4.8.11.

• Component boolean attributes are read as HTML does (DOMAttribute.parseBooleanValue): a bare one, an empty one
  or one set to its own name is on. <ui-dialog show> is shown, and <bui hide-from-menu> hidden (both were
  off). Explicit "true"/"false" values are unchanged. New parseAttributeBool reads one, or its default if
  absent: show, show-close-button, remove-on-hide and on-click-listen-only-for-dialog-button-class of
  <ui-dialog>, with-progress of <ui-button-loader>.

• InputConfig: a checked checkbox and a selected option also get the attribute (defaultChecked,
  defaultSelected), not only the property, so a form reset keeps them (it unchecked the box and selected the
  first option).

• Tests: boolean attributes in rendered components, <ui-dialog>, <bui> and InputConfig attributes
  (bones_ui_boolean_attributes_test.dart).

• Tests: a <ui-dialog remove-on-hide="false"> with a locale <select> in a <ui-template> (as an app's language
  menu), opened by an action="#id.show()": the option of the current locale is selected, also after the locale
  changes and the component (or the root) renders again; no copy of an earlier render is left in the page; a
  language picked with UIRoot.setPreferredLocale becomes the current locale, and a regional one (a browser's
  pt-BR) resolves to the language with messages (pt).