Decrease php usage by implementing LIMIT in requests to DB

[slaFFik]

The main idea is:
When php makes a request to sort some information (about groups, members, blogs) it's reasonable to add sometimes in bp-...-classes.php (-templatetags.php and not only there) in:

$wpdb->prepare("SELECT ...");

this:

$wpdb->prepare("Select ... LIMIT 50");

So not all groups, blogs, members will be stored, but 10, 50 or 100. This will definitely decrease php usage. And I'm sure, no need to display ALL users/groups/blogs in Random mode. 25 will be enough.

[apeatling]

There's pretty much always a limit set since there are pagination defaults set.