Need to make some refinements to the project pages

[jonfroehlich]

We've now updated the accessibility of project pages but need a few refinements.

1. Videos need to get stretched again in the background (like landing page)

2. The right sidebar needs more margin-top for the section headers. Things are bleeding together

3. When a project ends, we don't need to say "Former Student Leah" or "Former PI"

4. Long project names aren't wrapping. Maybe we just truncate them.

[jonfroehlich]

We are now properly truncating project names, which we added in b56824e and cbb825e