Merges an entry into the table, returns false on failure
Normally, merge succeeds, but in the GlyphTable implementation,
further constraints have to be followed.
Overridden so that we can copy the design from the
RENDERER of the cell over to the editor (copying over
foreground and background color, tool tip and font).
The history Vector for the glyph button and the dialog for that
plus the combobox used for the history and a JPanel to show
buttons and combo boxes which also hold the history
The renderman object provides us with a TableCellRenderer
implementation and some scrollTo(row) method, which
can be controlled by the processCommand() inside.
The current assignment between visible rows and internal rows,
some rows might be invisible so the values might differ!
used at different places, maintained by processCommand.
two tables, one for at most one key sequence for each glyph
and one where we can produce several glyphs by one key
sequence or assign several key sequences to the same glyphs.