Grids: implement goTabIgnoreAutoAdvance option.
If set (and goTabs in Options), then Tab key traverses grid like in aaRightDown mode,
much like tables in common wordprocessors.


git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@39938 4005530d-fff6-0310-9dd1-cebe43e6787f