Avoid redundant depreciation warnings in Visual Studio 2012

[lanzkron]

See the following stackoverflow question, deprecation warnings will show up even if nothing is used.

Note: I'm not able to clone the repository to my computer at the moment so this pull request was created on the web, please make sure it's OK.

[cdunn2001]

Moved to #669.

[jpo38]

@cdunn2001 Note that VS still reports deprectaed warning for StyledStreamWriter attributes childValues_, indentString_, indentation_ when json.h is included...it's unclear why it does that.

d:\dev\vobs_ext_2015\libcpp\jsoncpp\jsoncpp-1.8.3\include\json\writer.h(283): warning C4996: 'Json::StyledStreamWriter::childValues_': Use StreamWriterBuilder instead
d:\dev\vobs_ext_2015\libcpp\jsoncpp\jsoncpp-1.8.3\include\json\writer.h(310): note: see declaration of 'Json::StyledStreamWriter::childValues_'
d:\dev\vobs_ext_2015\libcpp\jsoncpp\jsoncpp-1.8.3\include\json\writer.h(283): warning C4996: 'Json::StyledStreamWriter::indentString_': Use StreamWriterBuilder instead
d:\dev\vobs_ext_2015\libcpp\jsoncpp\jsoncpp-1.8.3\include\json\writer.h(312): note: see declaration of 'Json::StyledStreamWriter::indentString_'
d:\dev\vobs_ext_2015\libcpp\jsoncpp\jsoncpp-1.8.3\include\json\writer.h(283): warning C4996: 'Json::StyledStreamWriter::indentation_': Use StreamWriterBuilder instead
d:\dev\vobs_ext_2015\libcpp\jsoncpp\jsoncpp-1.8.3\include\json\writer.h(314): note: see declaration of 'Json::StyledStreamWriter::indentation_'

[cdunn2001]

@jpo38, So we do need to push/pop the same thing for StyledStreamWrite? Or do we need to push a different suppression number? (I have no easy way to test this.)

[jpo38]

Yes, apparently this fixes it. And you'll later get the deprecated warning if you instantiate the class, what's expected.

[cdunn2001]

I unpushed. StyledStreamWriter should now suppress the warnings. Let me know if there is a problem.

[jpo38]

Works fine now.

By the way, did you get a chance to test this with g++. Because maybe it will complain that pragma is not recognized. You may need to protect the added lines by a #ifdef _MSC_VER check.

Thank you for the quick fix.

[cdunn2001]

We test both gcc and clang on Linux in TravisCI, and Microsoft on AppVeyor.