Entirely rework CapacityScaling (#180)

- Use the new interface similarly to NetworkSimplex.
- Rework the implementation using an efficient internal structure
for handling the residual network. This improvement made the
code much faster (up to 2-5 times faster on large graphs).
- Handle GEQ supply type (LEQ is not supported).
- Handle negative costs for arcs of finite capacity.
(Note that this algorithm cannot handle arcs of negative cost
and infinite upper bound, thus it returns UNBOUNDED if such
an arc exists.)
- Extend the documentation.

 /* The version string */

 #undef LEMON_VERSION

 /* Define to 1 if you have long long */

 #undef LEMON_HAVE_LONG_LONG

 /* Define to 1 if you have any LP solver. */

 #undef LEMON_HAVE_LP

 /* Define to 1 if you have any MIP solver. */

 #undef LEMON_HAVE_MIP

 /* Define to 1 if you have CPLEX. */

 #undef LEMON_HAVE_CPLEX

 /* Define to 1 if you have GLPK. */

 #undef LEMON_HAVE_GLPK

 /* Define to 1 if you have SOPLEX */

 #undef LEMON_HAVE_SOPLEX

 /* Define to 1 if you have CLP */

 #undef LEMON_HAVE_CLP

 /* Define to 1 if you have CBC */

 #undef LEMON_HAVE_CBC