Preserve the "end of list" flag for xls round-tripping.

This "end of list" flag determines whether the row insertion was an
automatic insertion at the bottom.  Calc doesn't use this at the moment
but Excel uses it to differentiate a normal row insertion from an
automatic one.

(cherry picked from commit adf0d7b1fb8eed88f4fcd6d31662ae6f59d00812)

Conflicts:
	sc/inc/chgtrack.hxx
	sc/source/filter/xcl97/XclExpChangeTrack.cxx

Change-Id: I6b28669d816c54d1dc1e4c106918ba688415788d