Previously, whatis would treat a word as [A-z0-9_] and terminate

Previously, whatis would treat a word as [A-z0-9_] and terminate
parsing an entry at the end of a word.  This kept things like
'whatis B::Bytecode' from working.  Now we match both on a word basis
as well matching until we hit a space, ',', or '(' character.
This allows one to say 'whatis B' and see the whatis line for B(3p)
as well as its methods (B::*).