[Fix #389] legend: handle EdgeColor and Color properly

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
Merge remote-tracking branch 'okomarov/fixLegendEdgeColor'
Fix `east` colorbars: use `addToOptions`

This might have been introduced in b2b74d787fea2742798f0c5abd37f7a05484542d
Merge branch 'fixColorbar'