fixes#973
- Done;
- Styling for Export button and tabular view
area in layout frame context;
- Export button in frame context now
hidden until user hovers over tabular
view area in frame, includes animated
transition;
- Normalized line-height on button and
menu elements in frame context;
- Layout/markup/SASS for historical and
RT tabular view modified;
- Converted imagery.html layout
to use flexbox;
8b9c51f303