ConfigDB.cpp: fix vfs_load return value check

baseentity, entity: remove multiple property adds (source of
scriptablecomplex memory leak)
scriptablecomplex: add code to check for leak regression and prevent
them; add suballocator for properties, since 60k are allocated in a
short while (!) - saves time and memory

This was SVN commit r3429.

source/scripting/ScriptableComplex.cpp

@@ -0,0 +1,38 @@
+#include "precompiled.h"
+#include "ScriptableComplex.h"
+
+// suballocator for CJSComplex.m_Properties elements
+static Bucket bucket;
+// HACK: it needs to be created/destroyed; since there is no
+// global init/shutdown call here, we keep a refcnt. this assumes that
+// going to 0 <==> shutdown! if that proves wrong, bucket_alloc will warn.
+static uint suballoc_refs;	// initialized in suballoc_attach
+
+void jscomplexproperty_suballoc_attach()
+{
+	ONCE(\
+		size_t el_size = MAX(sizeof(CJSValComplexProperty), sizeof(CJSComplexProperty<int, true>));\
+		(void)bucket_create(&bucket, el_size);\
+		suballoc_refs = 0;\
+	);
+	suballoc_refs++;
+}
+
+void jscomplexproperty_suballoc_detach()
+{
+	suballoc_refs--;
+	if(suballoc_refs == 0)
+		bucket_destroy(&bucket);
+}
+
+void* jscomplexproperty_suballoc()
+{
+	return bucket_alloc(&bucket, 0);
+}
+
+void jscomplexproperty_suballoc_free(IJSComplexProperty* p)
+{
+	// explicit dtor since caller uses placement new
+	p->~IJSComplexProperty();
+	bucket_free(&bucket, p);
+}