Various updates from Sam Bishop:

"I have been working my way through the JIT and Kaleidoscope tutorials in my
(minuscule) spare time.  Thanks again for writing them!  I have attached a
patch containing some minor changes, ranging from spelling and grammar fixes
to adding a "Next: <next tutorial section>" hyperlink to the bottom of each
page.

Every page has been given the "next link" treatment, but otherwise I'm only
half way through the Kaleidoscope tutorial.  I will send a follow-on patch
if time permits."

llvm-svn: 46933