Move to using the current_profile loaded in the session

[davemcg3]

current_profile is loaded into the session in profiles_controller#load_profile. This is currently only used in creating or editing wall posts but should be happening more ubiquitously. This would allow us to move closer toward the goal of allowing a user to have multiple profiles.

The goal here is to remove calls to current_user.profiles.first and replace them with calls to current_profile. This may take investigation into how devise sets current_user and doing something similar for current_profile.