Updated "Stored bytes over the last 7 days" graph title in dashboard

 - Updated title from "Stored bytes (GB)" to "Stored bytes"
New function UniformizeData() in CGraph class

 - the function UniformizeData() calculate the best unit (TB,GB,MB,etc.) for graphs
Fixed bug 0000113 - Bar plot graphs display data based on 1GB only
Fixed bug 0000130 - Y axis title is missing on some bar graphs

 - moved PHPLot object creation into CGRaph constructor()
 - added $width and $height parameter to CGraph class constructor
 - removed useless SetGraphSize() function from CGraph class
 - fixed typo in setLegend() function comment