When running 'script/stackprof object', I noticed that it would be helpful to see
GC information. It appears we create a lot of junk -- a source of optimization if
we decide to go down that path.
An average Jekyll build doesn't run a GC, but auto-regeneration likely would eventually
require a GC run and it would be interesting to see if we can reduce how much we throw
away with each call to 'site.process'.