Upgrade php from 5.3 to 5.4 in Ubuntu 12.04 LTS

By default, The version of PHP in Ubuntu 12.04 LTS is 5.3. Somehow, I need the features in 5.4 so that's why I wrote it down for future reference.

Commands
`sudo add-apt-repository ppa:ondrej/php5-oldstable`
`sudo apt-get update`
`sudo apt-get install php5`

If there is warning about missing a SSH module, 

clear the contents in /etc/php5/cgi/conf.d/ssh2.ini in order to eliminate the warning