Lua Fix utf8encode, remove utf16 functions

The auto generated utf8/16 encode/decode functions did not work.
Upon implementing them correctly I found that lua handles the utf-8
form properly but I could not get utf-16 to work without crashing
maybe someone can come along later and implement utf-16 safe string
functions but for now utf-16 is removed.

Change-Id: I97a044e200dc27f683a45487cd93fce667c670c4

apps/plugins/lua/rocklib.c

@@ -472,6 +472,16 @@ RB_WRAP(create_numbered_filename)
     return 1;
 }
 
+RB_WRAP(utf8encode)
+{
+    unsigned long ucs = (unsigned long) luaL_checkint(L, 1);
+    unsigned char tmp[9];
+    unsigned char *end = rb->utf8encode(ucs, tmp);
+    *end = '\0';
+    lua_pushstring(L, tmp);
+    return 1;
+}
+
 #define RB_FUNC(func) {#func, rock_##func}
 static const luaL_Reg rocklib[] =
 {
@@ -520,6 +530,9 @@ static const luaL_Reg rocklib[] =
 #if CONFIG_CODEC == SWCODEC
     RB_FUNC(pcm),
 #endif
+
+    RB_FUNC(utf8encode),
+
     {NULL, NULL}
 };
 #undef RB_FUNC

apps/plugins/lua/rocklib_aux.pl

@@ -70,6 +70,9 @@ my @forbidden_functions = ('^open$',
                            '^s?+rand$',
                            '^strl?+cpy$',
                            '^strl?+cat$',
+                           '^iso_decode$',
+                           '^utf8encode$',
+                           '^utf16',
                            '^codec_',
                            '^timer_',
                            '^lcd_(mono_)?+bitmap',