Two minor corrections to avoid warnings in make and make clean

There were two small warnings that are removed with this commit:

 - In the end, when we print the number of words in the PDF, we hadn't
   accounted for the fact that 'paper.pdf' doesn't always exist (for
   example when './project make clean' is run). So a check was added to
   only print the number of words when a PDF exists.

 - I noticed that the '$(texdir)/to-publish' directory was being built both
   in 'initialize.mk' and in 'demo-plot.mk'. So the one in 'demo-plot.mk'
   has been removed.

0 files changed, 0 insertions, 0 deletions