AP_Scripting: Reduce lua stack usage

libraries/AP_Scripting/lua/src/lfunc.h

@@ -26,7 +26,7 @@
 ** maximum number of upvalues in a closure (both C and Lua). (Value
 ** must fit in a VM register.)
 */
-#define MAXUPVAL	255
+#define MAXUPVAL	127
 
 
 /*

libraries/AP_Scripting/lua/src/lparser.c

@@ -31,7 +31,7 @@
 
 /* maximum number of local variables per function (must be smaller
    than 250, due to the bytecode format) */
-#define MAXVARS		200
+#define MAXVARS		100
 
 
 #define hasmultret(k)		((k) == VCALL || (k) == VVARARG)