Also, renames `ad_hoc_query.html` to `activity_table.html`,
`realm_summary_table.html` to `installation_activity_table.html`,
and `activity_details_template.html` to `activity.html`.
Removes the style attribute in the installation activity template
and uses a CSS class, "installation-activity-header", to center the
h3 and p tags instead. This removes an exception from the custom
lint check.
Lauryn Menard