Issue #1152: Fix occasional bad graphic for lines with multiple overlap symbols (fix incorrect sort function)
Issue #1152: Improved pedigree layout algorithm:
             - better positioning of new sibling nodes
             - better positioning of relationship lines
             - better pedigree compaction algorithm (i.e. less wasted horizontal space)
Issue #1152: Better horizontal edge positioning algorithm in pedigree editor
Issue #1152: Fixed pedigree compatibility with some browsers (a reserved keyword was used as a variable name)
Issue #1152: Added "navigate to proband" icon to navigation panel in pedigree editor