isSubscribed and hasBlocked need instance of Profile, not User

used by actions/apifriendshipsshow.php
make show more comments work with ajax loaded stuff, i.e. infinitescroll
make .attachment.more ajax work with ajax-loaded content, i.e. infiniteScroll
do favorites from default like in API

not quite sure about this, but the deleted code in this commit created
activity notices that we couldn't turn off in config.
repeat-bug, could not repeat oversized notices

this code is copy-paste from statusnet, apparently we need it still
we _do_ want to show text/html as attachments, since that's how mustard and crow expands oversized notices
groups/all didn't work, also fixed pagination in directory/users, and a convenient delete-button for admins
shows which user we are confirming to delete
remove dupes when infinitescrolling, and add infinitescroll to user lists and userdirectory also
i had introduced a bug... userdirectory didn't work when logged out