Remove ZeroedMemoryAllocator from ScriptText

Have ScriptText initialise all of its members on construction and
not derive from ZeroedMemoryAllocator.

(cherry picked from commit 3240126202d3437396004f2d5b0371783effb1ea)

Reorder ScriptText constructor initialisers.

src/script/api/script_text.cpp

@@ -30,7 +30,7 @@ RawText::~RawText()
 
 
 ScriptText::ScriptText(HSQUIRRELVM vm) :
-	ZeroedMemoryAllocator()
+	string(STR_NULL), params(), parami(), paramt(), paramc(0)
 {
 	int nparam = sq_gettop(vm) - 1;
 	if (nparam < 1) {

src/script/api/script_text.hpp

@@ -73,7 +73,7 @@ private:
  *
  * @api game
  */
-class ScriptText : public Text , public ZeroedMemoryAllocator {
+class ScriptText : public Text {
 public:
 	static const int SCRIPT_TEXT_MAX_PARAMETERS = 20; ///< The maximum amount of parameters you can give to one object.