Save only changed achievement data at player save. Some code cleanups.

Also increase tempory at stack buffere for utf8 convertion. It used in sql quaries log output and need have apporpriate size support.

src/shared/Util.h

@@ -287,7 +287,7 @@ bool Utf8FitTo(std::string str, std::wstring search);
 #if PLATFORM == PLATFORM_WINDOWS
 #define UTF8PRINTF(OUT,FRM,RESERR)                      \
 {                                                       \
-    char temp_buf[6000];                                \
+    char temp_buf[32*1024];                             \
     va_list ap;                                         \
     va_start(ap, FRM);                                  \
     size_t temp_len = vsnprintf(temp_buf,6000,FRM,ap);  \