updating standard headers to meet c++11 standard

When including stdint.h in c++ we can #define __STDC_LIMIT_MACROS so
that we get macros like INT32_MAX defined.

Also related is __STDC_CONSTANT_MACROS

I have recently found that the need for these has been removed within
the c++11 standard.

This year old bug report was to update glibc to this end -
https://sourceware.org/bugzilla/show_bug.cgi?id=15366

Also of note is that Apple removed the use of this macro from OSX with
the release of 10.9 over a year ago
http://www.opensource.apple.com/source/xnu/xnu-2422.1.72/EXTERNAL_HEADERS/stdint.h

I believe as we push to use llvm's libc++ and support for c++11 we
should also make sure the rest of our sources are kept up to date as
well.

Are there any other changes within c++11 or c++14 that we should be
looking to update?

Shane