Show Debug: no limit on the debug file

There is no limit on the size of the debug file, even though there is a limit to
how much of the file the user is seeing ("Only Displaying the last 2048K of file").

From an email from Jeff Theroux:
"If you're using the CCC with debug turned on, please periodically clear
the debug when it is no longer needed by opening the debug output page
and pressing the "clear" button. Files left uncleared for a long time
become rather large and could fill up the hard drive, which prevents
session data from being stored on the web server (can't log in to
AdMax/CCC)."

There should be a limit to how big the file is.