Improve and redesign test programs + unify their output (ticket #25)
- Move graph related utilities form test_tools.h to graph_test.h.
- Move the contents of graph_utils_test.h to graph_utils_test.cc.
- Rename map_test.h -> graph_maps_test.h.
- Rename digraph_test.h -> graph_test.h.
- Many improvements in the following files:
* digraph_test.cc
* graph_test.cc
* graph_test.h
* graph_maps_test.h
* graph_utils_test.cc
* bfs_test.cc
* dfs_test.cc
* counter_test.cc
- Test programs print messages only if it really seems necessary.
- Remove \file commands form .cc test files.

 syntax: glob

 *.obj

 *.orig

 *.rej

 *~

 *.o

 *.log

 *.lo

 *.tar.*

 *.bak

 Makefile.in

 aclocal.m4

 config.h.in

 configure

 Makefile

 config.h

 config.log

 config.status

 libtool

 stamp-h1

 lemon/lemon.pc

 lemon/libemon.la

 lemon/stamp-h2

 doc/Doxyfile

 .dirstamp

 .libs/*

 .deps/*

 demo/*.eps

 syntax: regexp

 (.*/)?\#[^/]*\#$

 ^doc/html/.*

 ^autom4te.cache/.*

 ^build-aux/.*

 ^objs.*/.*

 ^test/[a-z_]*$

 ^demo/.*_demo$

 ^build/.*

 ^doc/gen-images/.*

 CMakeFiles

 DartTestfile.txt

 cmake_install.cmake

 CMakeCache.txt