Adding Handle support to certain directives

Some WinJS widgets have methods e.g. hide/show or open/close that are
not exposed by the current WinJS shim for AngularJS. This patch adds
support for a "handle" attribute on those directives which when set
forces teh shim to put teh wdget instance in the scope as indicated by
teh value of the "handle" attribute.

Signed-off-by: Dylan Borg <borgdylan@hotmail.com>
adding handle publish to AppBar

Signed-off-by: Dylan Borg <borgdylan@hotmail.com>
Adding shown support on Navbar,AppBar,Flyout,Menu

* Also removing handle support in lieu of adding win-control directive

Signed-off-by: Dylan Borg <borgdylan@hotmail.com>
Adding win-control directive

Signed-off-by: Dylan Borg <borgdylan@hotmail.com>
Update README.md

This is an important step to making this library work.
Merge pull request #45 from NickHeiner/patch-1

Update README.md
Merge pull request #44 from borgdylan/borgdylan/handles

Adding Handle support to certain directives