Merge pull request #319 from Dashlane/visual-studio-build

Windows: Fix dynamic library build with Visual Studio

diff --cc json_object.h
index e3da64bb9bdf7d34d14ea3f4496020f8d33ee971,f6a86b0a51da872f669d6eefcbeb12db925fe5db..4bbc367b6199d4f4475bd71d250b92e79ccd7b5d
--- 1/json_object.h
--- 2/json_object.h
+++ b/json_object.h
@@@ -762,23 -752,8 +768,23 @@@ JSON_EXPORT struct json_object* json_ob
   * @param d the numeric value of the double.
   * @param ds the string representation of the double.  This will be copied.
   */
- extern struct json_object* json_object_new_double_s(double d, const char *ds);
+ JSON_EXPORT struct json_object* json_object_new_double_s(double d, const char *ds);
  
 +/**
 + * Set a global or thread-local json-c option, depending on whether
 + *  JSON_C_OPTION_GLOBAL or JSON_C_OPTION_THREAD is passed.
 + * Thread-local options default to undefined, and inherit from the global
 + *  value, even if the global value is changed after the thread is created.
 + * Attempting to set thread-local options when threading is not compiled in
 + *  will result in an error.  Be sure to check the return value.
 + *
 + * double_format is a "%g" printf format, such as "%.20g"
 + *
 + * @return -1 on errors, 0 on success.
 + */
 +int json_c_set_serialization_double_format(const char *double_format, int global_or_thread);
 +
 +
  
  /** Serialize a json_object of type json_type_double to a string.
   *