Fix build issues related to Solaris and older GCC

Fixed two build issues:
 - JsonCPP currently doesn’t compile for Solaris due to platform
differences with ‘isfinite’ function.  Fixed by adding proper include
and define for Solaris.
 - JsonCPP currently doesn’t compile for GCC version 4.1.2 and earlier
due to use of ‘-Werror=*’ compile flag, which was introduced in a later
version.  Fixed by adding version check to only add this flag on
supported versions of GCC.

src/lib_json/CMakeLists.txt

@@ -6,7 +6,6 @@ ELSE(JSONCPP_LIB_BUILD_SHARED)
   SET(JSONCPP_LIB_TYPE STATIC)
 ENDIF(JSONCPP_LIB_BUILD_SHARED)
 
-
 if( CMAKE_COMPILER_IS_GNUCXX )
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=strict-aliasing")
 endif( CMAKE_COMPILER_IS_GNUCXX )

src/lib_json/json_writer.cpp

@@ -26,6 +26,11 @@
 #pragma warning(disable : 4996)
 #endif
 
+#if defined(__sun) && defined(__SVR4) //Solaris
+#include <ieeefp.h>
+#define isfinite finite
+#endif
+
 namespace Json {
 
 static bool containsControlCharacter(const char* str) {