Adds @group docblocks to BP_Activity_Activity tests

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7126 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Adds tests for display_comments param of bp_has_activities() stack

Most of these tests currently fail, as it appears that there is no way to
exclude comments from the activity stream by using the querystring format

See #5029

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7127 cdf35c40-ae34-48e0-9cc9-0c9da1808c22