Colors are generated asynchronously now and the TimelineItem is
updated when the color generation finishes. This allows the UI
to stay responsive while new colors are being generated.
Author color is now cached so that it will not be re-calculated
each time a new message is posted. This cache gets cleared when
the theme is changed.
Additionally, the author color is now automatically refreshed
when the theme is changed, fixing the issue where you had to
change rooms before the colors would switch.
work regardless of the theme choices the user makes. The code
now incorporates the contrast between the background color and the
color generated by the user_name when picking colors. It currently
has two 'big' issues:
1. Colors are not cached. I am planning on adding a QHash for this
a little later. This should improve performance by not calculating
the color for the same users over and over and over again.
2. Theme changes do not trigger the colors to get refreshed.
Currently, you will have to switch to a different room and back
to get the colors to refresh.
