Automatically load wall of a profile that have just been followed

Current behavior: when a user follows a profile, its wall isn't automatically updated with its informations (you need to manually refresh the page).

Fix: when a user follows a profile, it automatically updates its information via ajax.

I also tried to improve some code style (i don't know if it goes against Noosfero's policy), so please, send me a feedback if anything is wrong and i'll fix as soon as I can.