Added a proposal for image lists.

redo/proposals/imagelist.md

@@ -0,0 +1,27 @@
+# Images in Tables and Trees
+
+In yet another "blame Windows" moment:
+
+```go
+type ImageList interface {
+	Add(image *image.Image)
+	Remove(index int)
+	Len() int
+}
+func NewImageList() ImageList
+
+type Table/Tree interface {
+	// ...
+	LoadImageList(ImageList)
+}
+
+type ImageIndex int
+```
+
+For Table, a field of type ImageIndex represents an index into the ImageList.
+
+For Tree, there is a field ImageIndex which contains the index of the entry.
+
+Note the name of the methods on both being LoadImageList(): the image list is copied, and any future changes will **not** be reflected. (This is to accomodate check boxes in Table, which must be done manually.)
+
+TODO appropriate size of images in an ImageList