Add missing documentation of the groups_members cache

Change-Id: Ia2449cf4a04d4e0472d092431c5abbf7d6295ab2
Set 'line-height: normal' for lines in side-by-side diff

On some browsers, accented characters are not displayed correctly
because the line is not high enough.

Bug: Issue 2970
Change-Id: I7a4e64f69f7d3c96a58d1bd1930d9f6c23896d14