added doc for installing from ubuntu package manager
added doc for installing from ubuntu package manager

Amadren/diaspora,KentShikama/diaspora,Amadren/diaspora,Muhannes/diaspora,jhass/diaspora,geraspora/diaspora,Muhannes/diaspora,Flaburgan/diaspora,geraspora/diaspora,despora/diaspora,diaspora/diaspora,Amadren/diaspora,KentShikama/diaspora,spixi/diaspora,Muhannes/diaspora,spixi/diaspora,diaspora/diaspora,spixi/diaspora,KentShikama/diaspora,geraspora/diaspora,spixi/diaspora,diaspora/diaspora,Muhannes/diaspora,SuperTux88/diaspora,SuperTux88/diaspora,Flaburgan/diaspora,SuperTux88/diaspora,Amadren/diaspora,KentShikama/diaspora,jhass/diaspora,despora/diaspora,Flaburgan/diaspora,diaspora/diaspora,SuperTux88/diaspora,despora/diaspora,despora/diaspora,Flaburgan/diaspora,geraspora/diaspora,jhass/diaspora,jhass/diaspora