... that is: "show" and "show on colored cells" ones

* change UI option for grid line display to tri-state drop down
* view option VOPT_GRID will take the information wheter to "Show"
  or "Hide" grid lines. New view option VOPT_GRID_ONTOP will take
  the information wheter to display grid lines on top of colored
  cells or not
* depending on VOPT_GRID_ONTOP grid lines will be drawn before or
  after drawing cell background in ScGridWindow::Draw
* store option as boolean property "GridOnColoredCells" (path:
  "/org.openoffice.Office.Calc/Layout/Line") in user config
* see
  http://wiki.documentfoundation.org/User:Andreschnabel/Spec_Calc_grid_lines_on_colored_background#UI_definitions
  for spec

in most situations it's much faster to use the iterator instead of the
manual loop + ScMarkData::GetTableSelect

Setting it to anything else moves field indexes off-by-N and causes crash
in some cases (the original code has been unused since 2004 at least)

local range names must be updated like global range names

add the current table number as fallback to the address parser for the
case that no table is specified

Now uses the values present in the import document
rather than calculating the formula. This speeds up
document loading.
TODO: Extend this to string results as well.

Remove BUTTONS_HELP_OK_CANCEL definition and use more
intuitive usable BUTTONS_OK_CANCEL_HELP.