trimmed release 18.0.1025.162
trimmed release 19.0.1084.52
trimmed release 20.0.1132.47
trimmed release 20.0.1132.57
trimmed release 21.0.1180.60
trimmed release 23.0.1271.97
trimmed release 24.0.1312.52
Remove special-case of tables for special elements

DRQS 37576223
The firstInSpecialElement and lastInSpecialElement functions handle tables
specially, in a way that doesn't make much sense.  I traced this behavior back
to revision 12358 in WebKit's SVN, which was committed in 2006.  It is likely
that this special case for tables made sense back then, but no longer makes
sense due to changes in other parts of the code since then.

The original behavior was causing DeleteSelectionCommand::initializeStartEnd to
modify the selection start/end positions to be outside the table element, which
resulted in the entire table getting deleted.
trimmed release 24.0.1312.56
trimmed release 25.0.1364.84
trimmed release 25.0.1364.152
trimmed release 26.0.1410.33
trimmed release 26.0.1410.43
trimmed release 27.0.1453.73
trimmed release 27.0.1453.94
trimmed release 27.0.1453.110
trimmed release 28.0.1500.95
Rebase 'bugfix/singleCellDelete' from upstream/23.0.1271.97 onto upstream/28.0.1500.95