Parse the detail message in a ClassNotFoundException
to extract the name of the missing class.
Unfortunately, this information is not directly available
from the exception object. So, this class parses the
detail message in several common formats (such as the
format used by BCEL).
author: David Hovemeyer
Get the name of the missing class from a ClassNotFoundException.
Parameters: ex - the ClassNotFoundException the name of the missing class, or null if wecouldn't figure out the class name