Disable live reloading by default.

I’m finding it incredibly annoying…our site has
gotten so large because of all the doc pages, and
the live reload behavior forces it to reload ALL
pages, not just the one I’m looking at, which takes
forever.  I wind up having to `kill −9` to get
the server to stop (ctrl-c doesn’t work).

Author: myronmarston

config.rb

@@ -6,7 +6,7 @@
 end
 
 # dev mode addons
-activate :livereload
+activate :livereload if ENV['LIVERELOAD']
 
 activate :blog do |blog|
   # This will add a prefix to all links, template references and source paths