Band listing

###### Main additions:
* User can create a listing for the band that s/he is a member of.
* My Band(s) link in navbar will filter bands the user created or is a part of.
* Band profile shows listings made under that band's name.
* Band member have full access to modify band profiles s/he is part of and listings created by his/her bands.
* User can add links/websites to band profile.