Add platform-specific installation instructions for APU.
Add platform-specific installation instructions for APU.

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