Migrate to VS 2015

[regisbsb]

Hi,

I was searching mixins on Google and found your project first page.
But because my company uses 2015 we cannot use pMixins.
Is there any possibility to migrate to 2015? 2015 should not be so different than 2013 I hope.

[Datafjott]

I wish I had the time to create a pull request for this, but alas.. If Philip could find time to make this, I would also be very happy.

[ppittle]

@Datafjott - A Pull Request would be most welcome :)

@regisbsb - I've also started using VS 2015, so it's been on my todo list to update [pMixins] to support VS 2015. I'm not sure the workload, but if it's not too high, I should be able to push it out soon-ish.