Revert "Update lua plugin to 5.2.3"

FILE typedef to *void needs more work to not break sim and
application builds. I checked only a few random native builds
unfortunately. Sorry for inconvenience.

apps/plugins/lua/strcspn.c

@@ -0,0 +1,17 @@
+#include "rocklibc.h"
+
+#undef strcspn
+size_t strcspn(const char *s, const char *reject)
+{
+  size_t l=0;
+  int a=1,i,al=strlen(reject);
+
+  while((a)&&(*s))
+  {
+    for(i=0;(a)&&(i<al);i++)
+      if (*s==reject[i]) a=0;
+    if (a) l++;
+    s++;
+  }
+  return l;
+}