Users display_name problems in rare cases [with patch]

[slaFFik]

One user on my local install doesn't have fullname and display_name. so In the loops he is displaying without name at all - just an avatar. Bad.

I created a patch, that behaves using this logic:
1) if no fullname - use display_name (default)
2) if no default name - use nice_name, which is username in most cases.

So in rare cases users will be have at least nice_name instead of nothing.

[DJPaul]

Is user_nicename always guaranteed to be set?

[boonebgorges]

(In [4890]) Ensure that bp_get_member_name() always returns a fullname value. Fixes #3404. Props slaFFik

[johnjamesjacoby]

Moving closed ticket out of Awaiting Review.