Add documentation regarding switching to root.
Add documentation regarding switching to root.

fabiokung/passenger-debian,antek-drzewiecki/passenger,openSUSE/passenger,antek-drzewiecki/passenger,gravitystorm/passenger,clemensg/passenger,phusion/passenger,openSUSE/passenger,bf4/passenger,cgvarela/passenger,clemensg/passenger,openSUSE/passenger,pkmiec/passenger,antek-drzewiecki/passenger,antek-drzewiecki/passenger,bf4/passenger,erikogan/passenger,erikogan/passenger,pkmiec/passenger,pkmiec/passenger,erikogan/passenger,phusion/passenger,kewaunited/passenger,antek-drzewiecki/passenger,jawj/passenger,erikogan/passenger,phusion/passenger,clemensg/passenger,kewaunited/passenger,pkmiec/passenger,antek-drzewiecki/passenger,fabiokung/passenger-debian,phusion/passenger,pkmiec/passenger,pkmiec/passenger,cgvarela/passenger,jawj/passenger,erikogan/passenger,jawj/passenger,clemensg/passenger,antek-drzewiecki/passenger,phusion/passenger,openSUSE/passenger,cgvarela/passenger,bf4/passenger,jawj/passenger,openSUSE/passenger,kewaunited/passenger,gravitystorm/passenger,cgvarela/passenger,jawj/passenger,pkmiec/passenger,bf4/passenger,antek-drzewiecki/passenger,phusion/passenger,kewaunited/passenger,bf4/passenger,kewaunited/passenger,gravitystorm/passenger,gravitystorm/passenger,bf4/passenger,fabiokung/passenger-debian,erikogan/passenger,cgvarela/passenger,openSUSE/passenger,clemensg/passenger,kewaunited/passenger,clemensg/passenger,bf4/passenger,phusion/passenger,clemensg/passenger,cgvarela/passenger,jawj/passenger,fabiokung/passenger-debian,clemensg/passenger,cgvarela/passenger,kewaunited/passenger,phusion/passenger,fabiokung/passenger-debian,kewaunited/passenger,fabiokung/passenger-debian,gravitystorm/passenger,cgvarela/passenger,jawj/passenger,gravitystorm/passenger