0022898: IGES import fails in german environment

Added DRAW command dlocale to set and query current locale of the C subsystem
Equivalents of C functions working with conversions of strings to/from reals added in Standard_CString, providing locale-independent behavior (using always "C" locale)
In DRAW packages, calls to atof() and atoi() are replaced by direct calls to Draw::Atof() and Draw::Atoi(), respectively, instead of substituting by #define
Use of atof(), strtod(), and *scanf() involving floating point conversions in OCCT code replaced by locale-independent Atof() and Strtod()
Calls to sprintf() involving floating point in OCCT code are replaced by call to locale-independent Sprintf(), except a few places where converted strings are used immediately for display in the 3d viewer
Changes of global locale are eliminated throughout OCCT code
Proposed correction for GNU libC where v*printf_l functions are absent
Added test case (bugs xde bug22898) for data exchange operations with non-standard locale
Use xlocale on Mac OS X and within glibc
Corrected strtod_l wrapper
Generate error rather than warning
Introduce Standard_CLocaleSentry replacement for removed OSD_Localizer
Standard_CLocaleSentry - copy locale string
Standard_CLocaleSentry - use _configthreadlocale on Windows
Standard_CLocaleSentry::GetCLocale() - return locale_t rather than void*
Corrected misprint in ~Standard_CLocaleSentry()
Use French locale in bug22898 test case
Mark test case as skipped if locale is unavailable on tested system.
Use fr_FR locale for tests on Mac OS X

src/PCollection/PCollection_HAsciiString.cxx

@@ -402,7 +402,7 @@ Standard_Boolean PCollection_HAsciiString::IsRealValue () const
    for(i = 0; i < astring->Length(); i++)
                             cnvbuf[i] = astring->Value(i+1);
    cnvbuf[i] = 0;
-   cnvreal = strtod(cnvbuf,&ptr);
+   cnvreal = Strtod(cnvbuf,&ptr);
    if (ptr < cnvbuf+astring->Length()) return Standard_False;
    else                                return Standard_True;
 }