Baseline bump to MSVC 2015 Update 3

[David Ostrovsky]

On Thu Mar 2 20:53:46 UTC 2017 Caolán McNamara wrote:

>>On Thu, 2017-03-02 at 17:02 +0100, Stephan Bergmann wrote:
>>[...]
>
>That means that _MSC_VER is always >= 1900 (?), I presume, outside of
>the headers exposed through the sdk, that means we can remove the
>ifdef branches that support earlier versions of that now ?

Yes, but please check first what is already pending for review: [1].

* [1] https://gerrit.libreoffice.org/#/q/topic:toolchain-cleanup