store log file in ~/.config/nblood/

Index: source/blood/src/blood.cpp
--- source/blood/src/blood.cpp.orig
+++ source/blood/src/blood.cpp
@@ -1586,6 +1586,29 @@ int app_main(int argc, char const * const * argv)
         Xfree(homedir);
     }
     else
+#else
+    if (!g_useCwd)
+    {
+        char cwd[BMAX_PATH];
+        char *homedir = Bgethomedir();
+        int r;
+        if (homedir)
+        {
+            Bsnprintf(cwd, sizeof(cwd), "%s/.config/%s", homedir, APPBASENAME);
+            r = Bmkdir(cwd, S_IRWXU);
+            if (r == 0 || (r == -1 && errno == EEXIST)) {
+                Bsnprintf(cwd, sizeof(cwd), "%s/.config/%s/%s.log",
+                    homedir, APPBASENAME, APPBASENAME);
+            } else {
+                Bstrcpy(cwd, APPBASENAME ".log");
+            }
+        } else {
+            Bstrcpy(cwd, APPBASENAME ".log");
+        }
+        OSD_SetLogFile(cwd);
+        Xfree(homedir);
+    }
+    else
 #endif
     OSD_SetLogFile(APPBASENAME ".log");
 
