[easytag] Update HACKING for GtkBuilder UI files

[David King <davidk src gnome org>]

commit 43c76c81c075734147a11b413e3941b1f4d085f9
Author: David King <amigadave amigadave com>
Date:   Sat Sep 20 11:28:17 2014 +0100

    Update HACKING for GtkBuilder UI files

 HACKING |   10 ++++++++++
 TODO    |    1 -
 2 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/HACKING b/HACKING
index 2fc7bb5..2d0621c 100644
--- a/HACKING
+++ b/HACKING
@@ -36,3 +36,13 @@ indents. This has been changed slightly to the following guidelines:
 * function return values on a line separate from the function name
 
 New code should follow this style.
+
+GtkBuilder UI descriptions
+--------------------------
+
+GtkBuilder files are used for describing the EasyTAG UI. The UI files are in
+the data directory, and named *.ui. The files are not created with Glade, and
+Glade should not be used to edit them, as it will unnecessarily rearrange
+content within the file, leading to commit diffs which are difficult to read.
+The files are not installed, but instead compiled into a resource bundle and
+built into the application binary.
diff --git a/TODO b/TODO
index 032eb0d..7252782 100644
--- a/TODO
+++ b/TODO
@@ -31,7 +31,6 @@ Tagging features
 UI work
 -------
 
-* Use more of the standard GTK+ widgets, for example GtkAboutDialog
 * Use a Nautilus-like path bar for directory selection
 * Detect when the main window is too large to fit on the screen
 ** Reflow tagging UI in order to fit on screen