Small implementation improvements in MCF algorithms (#180)

- Handle max() as infinite value (not only infinity()).
- Better GEQ handling in CapacityScaling.
- Skip the unnecessary saturating operations in the first phase in
CapacityScaling.
- Use vector<char> instead of vector<bool> and vector<int> if it is
possible and it proved to be usually faster.

#define LEMON_VERSION "@PROJECT_VERSION@"

#cmakedefine LEMON_HAVE_LONG_LONG 1

#cmakedefine LEMON_HAVE_LP 1

#cmakedefine LEMON_HAVE_MIP 1

#cmakedefine LEMON_HAVE_GLPK 1

#cmakedefine LEMON_HAVE_CPLEX 1

#cmakedefine LEMON_HAVE_CLP 1

#cmakedefine LEMON_HAVE_CBC 1