statically linking to prebuilt libsoundio.a in msvc

[malytomas]

unresolved external symbols: __imp___iob_func, __mingw_vfprintf, __mingw_vsnprintf

it also emits a warning, which I do not really understand:
MSVCRT.lib(std_type_info_static.obj) : warning LNK4078: multiple '.drectve' sections found with different attributes (00100A00)

using libsoundio 1.1.0
using msvc 2015 (14, update 2)

side note: dynamic linking works fine, although, it took me quite some time to realize, that i can use the .a file as if it was .lib :D

[andrewrk]

Hmm, I think this means we need to provide an MSVC static lib, along with cross compiled mingw libs, when we release. Now that libsoundio compiles with MSVC, or at least will very soon (#49), this will be fixed with the next release.