Two bugs in Drupal.behaviors.bootstrapAnchors

Bugs in `Drupal.behaviors.bootstrapAnchors` method `bootstrapAnchor`

bug 1

When you have a link of "#" the first check for $target.length will be falsey.
Then the second attempt will search for `[name=""]`
The problem here is that if you have any element with an empty name attribute it
will be used as the $target and the link will scroll to an unexpectd point rather than doing nothing.
Yes a solution is to not output a name attribute if its empty, however several Drupal modules
will still output the name attribute on a button or input even if it is empty.

This can be fixed by altering the following:

// Check for anchors that use the name attribute instead.
if (!$target.length) {
  attr = 'name';
  $target = $('[name="' + element.hash.replace('#', '') + '"]');
}

To:

// Check for anchors that use the name attribute instead.
if (!$target.length) {
  attr = 'name';
  var name = element.hash.replace('#', '');
  if(name !== '') {
    $target = $('[name="' + name + '"]');
  }
}

bug 2

A link with a hash that doesn't exist on the page will cause the script to throw an error.
ie. <a href="#this_probably_doesnt_exist_on_your_page">test</a>

This can be fixed by altering the following:
(because the anchor is valid even theo theres no target it doesn't exit)

// Immediately stop if no anchors are found.
if (!this.validAnchor && !$target.length) {
  return;
}

To:

// Immediately stop if no anchors are found.
if (!this.validAnchor || !$target.length) {
  return;
}