Allow initializing wxScopedArray more conveniently.

Typical wxScopedArray initialization uses "new T[n]" expression, allow to omit
most of it and specify just n, the number of elements to allocate.

Use the new shorter form in the places where wxScopedArray(new ...) was used
(which is in almost all of them)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75504 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -9,6 +9,10 @@ Note: This file contains the list of changes since wxWidgets 3.x, please see
 3.1.0: (released 2014-xx-xx)
 ----------------------------
 
+All:
+
+- Add wxScopedArray ctor taking the number of elements to allocate.
+
 All (GUI):
 
 - XRC handler for wxAuiToolBar added (Kinaou Hervé).