*.pod changes based on the FAQ

*.pod changes based on the FAQ

After the faqqing dust has settled, it looks like a couple of the
things in the FAQ aren't mentioned in the pods and should be.  I came
up with a list of possible changes, and have implemented all but:
 - Need a discussion of optimising for speed/size, including compiling,
   autosplitting, etc.
 - The buffering discussion from part5 belongs somewhere.
 - The explanation of C<..> in perlop is confusing.  Then again, C<..> is
   confusing.

p5p-msgid: 199703171650.JAA02655@elara.frii.com