Base-level replacement of the Vision-derived text RunView― a couple
important features supported by the replacee haven't been implemented yet,
including:
* Right-click menu
* URL-highlighting/selection
* Emote support
This makes it so RunView's built-in timestamps are used― but requires
that a time_t be sent with each newly-appended line. This allows for lines to
be backdated or forward-dated.
Allows custom colors to be dictated to RunView directly from
CayaRenderView. Some colors that were reliant on hard-coded theme
have been replaced with system colors.