Applied the changes which somehow vanished during my last merge. Thanks goes
to Marci for noticing this. In detail:
- added amsmath and amssymb latex packages for latex documentation
- src/demo is also scanned for doxygen input files

 BINARIES = error_test

 INCLUDEDIRS= -I. -I.. -I../.. -I../{marci,jacint,alpar,johanna,athos,akos} -I$(HOME)/boost

 include ../makefile

 CXXFLAGS += $(C)