Commits for review: Add php Error Reporting Functionality to PMA

Add php Error Reporting Functionality to PMA.
I had used that function earlier to get the stack backtrace. No need for it now. Should have removed this change in [Send only backtrace (not displayBacktrace). Change getBacktrace to return first 'X' frames. Send stackhash too.](https://github.com/dhananjay92/phpmyadmin/commit/d08ef1d21f270ffceb042721f4c8f21e351d5cb4)
Anyway, I've removed it during the rebasing. See new [L#272 @Error.class.php](https://github.com/dhananjay92/phpmyadmin/blob/dhananjay-gsoc-rebased/libraries/Error.class.php#L272).