[GMC] expanding tree changes focus of right pane

["BASS, Ned" <nbass shl com>]

Expanding a tree in the left pane by clicking the plus sign changes the
focus of the right pane to the expanded folder.  This is probably the
intended behaviour, but I find it useful to be able to select some files in
the right pane, and then be able to expand trees in the left pane without
losing my place in the right pane.  This makes it easier to drag files from
the right panel to a desired location in the left pane.  This is how I
suggest that the behaviour should be:

Clicking the plus sign by a parent directory to expand it does not change
the focus of the right pane.

Double clicking a parent direcotry to expand it does change the focus of the
right pane.

Ned