Add drag-and-drop support, both in to find a character and out to copy a character

Scroll with wheel, page up/down, or scroll bar shall adjust the character selection to remain in view

Show font and upscaled (based on same font size) glyph when Shift is held
(note: selection change via gcmap_char_table_key_press may require update)

Show font and upscaled (based on same font size) glyph when mouse button 3 (right)
is held down; this shall also select the character and do so continuously while
moving the pointer

Middle-clicking should find the character stored in PRIMARY (SECONDARY if Mod1 is held down)

Keep selected character in view when resizing the chart or the cells

Optionally show metrics

Add bookmarks expander under the tabbed pane

Mark whenever a fallback font is used for a glyph

Mark reserved, non-printable, and unassigned characters

Add handheld-layout (with compile-time opt-in as default):
	alternative 1: put group list, as combo box, above table
	alternative 2: put group list as tab
	also: skip the menubar (but add the accelerators)

Remember some settings

Add font blacklist

Add support for command line operands: select listed fonts by path

Add editor to font drop-down to make it easier to select a font

Scrolling inside a GtkScrolledWindow or LogicalScrollPane shall steal focus (gtk_widget_grab_focus)

Scrolling with Control held down shall change zoom. The hovered cell shall
remain visible, preferably at the same Y position as the pointer. The pointer
shall jump to the new position of the cell so account for it being impossible
to ensure that cell remains at the same X position as the pointer.

Under "Go" add option to go to the same character in:
	- All
	- Block
	- Primary script
	- Next secondary script
	- Previous secondary script

Add command line options for opening into a specific character or codepoint

Fix XXX's