Added Visual Studio solution

Does not build yet, but that's to come. Next steps are to try finding
nice equivalents for the used, but unsupported-in-VS C++11 features.
Fixed endianness detection for MSVC.

Since Visual Studio targets only Windows and Windows only runs on little-endian architectures we can just hardcode the detection. This is even nicer because there does not seem to be a reliable preprocessor-stage detection of platform endianness.
Use doubly braced initializer lists in tests.
Replace std::iota with simple for loop.
Disable static compilation tests of AmfVector on Windows.
Work around bug(?) in VS2013.

When creating the vector with an initializer list containing a
temporary AmfString, the vector element is default constructed, thus
having the value "".
Remove time_t ctor for AmfDate.

In VS on x64, time_t is equivalent to long long, so it's impossible
for the compiler to figure out which constructor to use.
Fix localtime test in VS.
Note the VS2013 requirement in the README.