implemented multi-page pdf using latex, for multiple src files
handling multiple graphs
checking existence of nodes in other files, otherwise no (dead) latex
 hyperref link created
all edges black
custom dot export complete, using Pydot next to be added

new preprocessing option (cflow --cpp) to handle files with
 heavy usage of preprocessor directives (otherwise cflow fails)
upgrade to cflow v1.4 (interface the same)

automatic latex multi-page compilation next to be implemented
priting Copyright notice upon startup
more func refactoring