Big changeset messages cause problems on smaller screens

Refer to FSH-2577.

If the message of the changeset contains multiple lines, it takes up too much space. So on smaller screens it's impossible to see the content below.

It would be useful to have the ability to expand/collapse the message.

See the following screen shots:

resolution	screenshot
at 1024x768
at 600x800

Workaround for now would be to collapse the left navigation bar:

at 600x800 navbar collapsed