…s (linkInactiveClass, linkExactInactiveClass)

There are non-trivial situations where playing with CSS selectors becomes too inconvenient. Consider the following markup:
    <div>
      <div class="tabs_account">
        <div class="tab_spacer">&nbsp;</div>
        <template v-for="page in $router.currentRoute.parent.children" v-if="page.can_show">
          <router-link tag="div" active-class="tab_active" inactive-class="tab" v-bind:to="page.path">{{ page.title }}</router-link>
          <div class="tab_spacer">&nbsp;</div>
        </template>
        <div class="tab_fill tab_spacer">&nbsp;</div>
      </div>
      <router-view></router-view>
    </div>
You can achieve the same effect like this
<router-link :class="{'router-link-active': $route.fullPath ==='/' || $route.fullPath === '/a'}" to="/a"></router-link>
but it looks hacky (you have to keep the PATH in HTML in sync with the JavaScript code) while my proposed solution feels more elegant.

…, parent, title)

It is not easy to get access to child routes when you need to render nested menus with <router-link>
Publishing "children" on the $route.currentRoute solves a real problem. The "parent" property is required so that the route can see its siblings. The "title" property is optional - it is useful instead of "name" when you want to name a route having a default child. I personally use "name" in beforeRouteEnter/beforeRouteUpdate to update the "document.title" in browser - and I need it on all routes (even with default child), so I had to add "title" property.

This closes issue #1149

…rty for CSS class on inactive router links

The $router.currentRoute object now exposes "children[]" and "parent" properties.
The <router-link> component has now properties "inactive-class" and "exact-inactive-class" for specifying CSS class on inactive routes.

Solves issue #1149