fdo#70499 selectn of lock/unlocked cells with worksheet protection reversed

The ooxml spec documentation is rather confusing ( for me at least ) and the
sense of the of the sheetProtection attributes as described seems reversed to
how I read it ( or maybe it is the equivelant option in ScTableProtection that
operates with the reverse sense <shrug>  ) In anycase the import ( and export )
have been adjusted to take that into consideration, also the export now actually
deals with the defaults correctly.

Change-Id: Ia69567b8898b39c9d171486cfa800e1748c5814b