Update functions.inc.php

On 2.1.4 and tested the default functions.inc.php and the memory % still showing 1/2 of the actual used %, you took my changes to the system widget which fixed the total mem shown, but this code pull with the code I entered will show the correct % once it goes above 1024MB. I also added to my box code that will convert the total mem shown from MB to GB depending on the total system memory IE if 512MB is shown it will show 512MB. If total mem is 1024MB it will display 1GB and so forth. I can add that if you would like.