Rename tech notes to files with reasonable names.

Keep the old files to avoid breaking existing links to them, but just point to
the files in the new contributing subdirectory with more meaningful names now.

Also remove a couple of long obsolete tech notes.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76689 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/contributing/how-to-add-new-xrc-handler.txt

@@ -0,0 +1,54 @@
+                         How to add a new XRC handler
+                         ============================
+
+0. Purpose
+----------
+
+This note describes what needs to be done to add a new XRC handler, i.e. add
+support for loading the objects of some class wxFoo from XRC.
+
+
+1. Implement the handler
+------------------------
+
+By convention, the XRC handler for a class wxFoo declared in wx/foo.h is called
+wxFooXmlHandler and is declared in the file wx/xrc/xh_foo.h (this last rule
+wasn't always respected in the past, however it's not a reason to not respect
+it in the future). The steps for adding a new handler are:
+
+a) Add handler declaration in include/wx/xrc/xh_foo.h, it will usually be the
+   same as in the other files so you can get inspiration for your brand new
+   handler from e.g. wx/xrc/xh_srchctrl.h. Notice the use of wxUSE_FOO if wxFoo
+   is guarded by this symbol.
+
+b) Add implementation in src/xrc/xh_foo.cpp: again, it will be almost always
+   very similar to the existing controls. You will need to add support for
+   the control-specific styles.
+
+
+2. Update the other files
+-------------------------
+
+There are a few other files to update to make wxWidgets aware of the new
+handler:
+
+a) Add the new files created above to build/bakefiles/files.bkl: search for
+   "xh_srchctrl" to see where you need to add them
+
+b) Add #include "wx/xrc/xh_foo.h" to wx/xrc/xh_all.h.
+
+c) Register the new handler in wxXmlResource::InitAllHandlers() in
+   src/xrc/xmlrsall.cpp
+
+
+3. Update the sample
+--------------------
+
+Demonstrate that the new handler works by adding a control using it to
+samples/xrc/rc/controls.xrc.
+
+
+=== EOF ===
+
+Author:  VZ
+