title: change date process maker to persian date ( jalali ) or add date picker jalali
body: <p>I want to change dates shown everywhere in processmaker to another format(Persian calendar). I have my custom class to format dates. What is the best way to override the default function which returns the formatted date? I just found the CurDate method in the G class. Changed it's returned value but dates are still shown in gregorian format. Is there any other method for formatting dates?</p>
  
  <p>I prefer an OOP solution to override the default function instead of hacking the core, if possible.</p>
  
  <p>Thanks.</p>