Add a "reinitialize" method

[tigerhawkvok]

Addresses issues like #258 (and #185 , which seems to be related), or allows content to be dynamically added outside of a <dom-module> like #180 , #263 .

In the case any of those are hit, it provides an immediate workaround (possibly in conjunction with a helper thing like isVisible(), but that could be left to the person using the component)

[ebidel]

We should fix the issues rather than provide a workaround.

[Kadajett]

I am currently running into a bug with this, where I am dynamically adding google-map-markers to the dom, but the map is not showing the markers. I have tried the Polymer.dom().appendChild() workaround, but it didn't seem to work. Any Tips?

edit FYI: They are being injected into the DOM properly, just not displaying.

[framled]

my solution was, create a new infowindow every time when user click on google-map-marker