improve type safety for table layout utils

Some methods in the table layout system used an offset instead of an
ContentPosition. This caused a IllegalArgumentException in
LayoutUtils#elementOrRangeContains. This method is replaced by a
typesafe class.

Change-Id: I3dc9ea4fcdc0c6e258a3b46a60bb74bd49786b30
Signed-off-by: Carsten Hiesserich <carsten.hie@gmail.com>
8 files changed