qd-methods.lisp:

o Oops.  Move COERCE to qd-complex.lisp because we use the #q reader
  macro.  (This needs to be reorganized better.)
o Add RANDOM methods so we can generate quad-double random numbers.

qd-package.lisp:
o Shadow RANDOM so we can add our own RANDOM to generate quad-doubles.

qd-complex.lisp:
o COERCE moved here.