Improve the function-type interface of bfs, dfs, and dijkstra (ticket #96)
- BfsWizard and DfsWizard have run(s), run(s,t), and run() functions,
DijkstraWizard has run(s) and run(s,t) functions.
- Set NodeMap<T> instead of NullMap as PredMap and DistMap in the default
traits classes for the function-type interface.
- Modify the related test files.
- Doc improvements.
- Bug fix in concepts/path.h.

 prefix=@prefix@

 exec_prefix=@exec_prefix@

 libdir=@libdir@

 includedir=@includedir@

 Name: @PACKAGE_NAME@

 Description: Library of Efficient Models and Optimization in Networks

 Version: @PACKAGE_VERSION@

 Libs: -L${libdir} -lemon

 Cflags: -I${includedir}