install VirtualBox on LinuxMint(Ubuntu)

- https://www.virtualbox.org/wiki/Linux_Downloads

단순히 'apt-get update; apt-get install virtualbox' 하면 잡다한 에러가 발생...

1. vi /etc/apt/sources.list

  deb http://download.virtualbox.org/virtualbox/debian trusty contrib

2. add Oracle public key

  wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -

3. apt-get update ; apt-get install dkms ; apt-get install virtualbox-4.3