draft vector tile directive with example

[snodnipper]

quick stab at adding a vector tile directive. Perhaps this is something folk can refine?

I note that the lifecycle doesn't behave quite right - I seem to need to click onto, say, 'Set Basemap' before 'Vector Basemap'. Perhaps someone can comment.

Happy to rebase as necessary.

[tomwayson]

@snodnipper

Thank you for this thorough contribution (including docs!). I definitely plan to merge this, but I've been seeing the same issues you mention above and haven't had time to dig into it yet.

@jwasil this is on the roadmap now, so whomever gets a chance to work on it first should just self-assign this PR.

[snodnipper]

No worries Tom - glad you found it useful. I will be keen to see what the issue is.

[jwasilgeo]

@snodnipper I'd like to echo @tomwayson's comment: thanks for your work on this! I have been investigating and have some thoughts on what is causing this. I'll let you know when I have some commits of some changes worth mentioning pretty soon.

[jwasilgeo]

Refer to #182 for more info.

[tomwayson]

Thanks again @snodnipper!

[snodnipper]

Np guys! Happy Christmas and may 2016 be full of Angular 2 gorgeousness!