graph_io under construction
This is a working version, but needs more improvments.

todo:
documention + fix the file format
improve the exception system

add some possible asserts

tutorials

 BINARIES = tag_demo

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

 include ../makefile