When saving state for a 3-columns headerview and then restoring that
state onto a 5-column headerview, the headerview shouldn't suddenly think
it has 3 columns.
Rather than making restoreState() fail, we adjust for the additional
columns, so that we can still apply the customizations from the user to
all other columns (hiding, moving, etc.).
Change-Id: I3f220aa322ea8b629d2fe345f8cde13e0ea615d6
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
77a8e90cdd