lazy loading of tab contents

[ghost]

Hi Lukas, thanks for v-tabs, a pretty nice alternative to the usual bootstrap tabsets.
To make it even more valuable I recommend to add configurable lazy-loading to v-tabs. The expected behaviour should be : once I configure v-tabs to use lazy-loading, it should load the tabs contents only if the tab gets active the very first time. When I walk through three tabs I'd want them to be initialized only once the first time a tab gets active and then kinda cache the contents (like vtabs does it now). Would you be able to add that ?