Compilation error in PolyString.cpp (on VS2010)

[halogenica]

In a recent change, isNumber() added a call to std::isdigit. This does not appear to resolve to a valid function in VS2010 with the given includes. As an alternative, a cross platform version of "isdigit" is available in "locale.h".

For reference, a very brief comment indicating the locale.h solution to the issue: http://stackoverflow.com/questions/3108282/unicode-supported-isdigit-and-isspace-function

[ivansafrin]

I fixed it by ifdefing it out awhile ago, but still needs to be implemented on windows.