Build system: added test for beamer

git-svn-id: https://www.dynare.org/svn/dynare/trunk@2955 ac1d8469-bf42-47a9-8791-bf33cf982152

Makefile.am

 if HAVE_PDFLATEX
+if HAVE_BEAMER
 pdf-local: macroprocessor.pdf
 endif
+endif
 
 SRC = macroprocessor.tex old-design.pdf new-design.pdf