Use iterators to make some logic clearer
Use Option functions to make logic clearer
Make move mutation out of compute_minimum_ascent_and_descent
Remove some unnecessary mutable references
Use Option::expect instead of pattern matching in try_append_to_line_by_new_line
Clean up skip_while iteration
Merge pull request #2682 from bjz/assorted-cleanups

Assorted cleanups in gfx and layout