Active Menu Link Improvements

There have been numerous issues created around the automatic active-state detection (#25, #32, #42, and #43). This issue will replace all the other open issues to keep things consolidated in one location.

The active-state detection does not take into consideration dynamic URI segments that may be attributed to the menu item. Below we'll look at an example.

We have a menu defined as follows:

Menu::make('example', function($menu) {
    $menu->add('Blog', '#');
    $menu->blog->add('Manage Posts', 'admin/blog');
    $menu->blog->add('Write New Post', 'admin/blog/create');
});

The following URI's trigger the active state as defined:

URI	Triggers	Should Trigger
`admin/blog`	`Blog` and `Manage Posts`	`Blog` and `Manage Posts`
`admin/blog/create`	`Blog` and `Write New Post`	`Blog` and `Write New Post`
`admin/blog/edit/1`	`N/A`	`Blog`

caffeinated / menus

Active Menu Link Improvements #44