Set the tag type in libtool invocations
Setting the tag type will let libtool work even when it cannot infer
the type of the code being built. One way libtool may fail to infer
the tag type is if one uses a mock compiler (such as for static
analysis).
Added a README file regarding WinRT support
To note, this file is currently formatted with CRLF line endings, rather than
LF, to allow the file to be viewed with Notepad.
