tb Enable/disable command logging dynamically + setlogcmds builtin

user/tb/config.h

@@ -0,0 +1,20 @@
+#ifndef TB_CONFIG_H_
+#define TB_CONFIG_H_
+typedef struct {
+  char *modestr;
+  enum {
+    MODE_INTERACTIVE = 1,
+    MODE_RUNFILE = 2,
+    MODE_RUNSTRING = 3,
+  } mode;
+
+  char *filepath;
+
+  bool logcmds;
+
+  char *runstring;
+} Config;
+
+extern Config CONFIG;
+
+#endif // TB_CONFIG_H_