Entirely rework cycle canceling algorithms (#180)

- Move the cycle canceling algorithms (CycleCanceling, CancelAndTighten)
into one class (CycleCanceling).
- Add a Method parameter to the run() function to be able to select
the used cycle canceling method.
- Use the new interface similarly to NetworkSimplex.
- Rework the implementations using an efficient internal structure
for handling the residual network.
This improvement made the codes much faster.
- Handle GEQ supply type (LEQ is not supported).
- Handle infinite upper bounds.
- Handle negative costs (for arcs of finite upper bound).
- Extend the documentation.

 SET(LEMON_INCLUDE_DIR "@CMAKE_INSTALL_PREFIX@/include" CACHE PATH "LEMON include directory")

 SET(LEMON_INCLUDE_DIRS "${LEMON_INCLUDE_DIR}")

 IF(UNIX)

   SET(LEMON_LIB_NAME "libemon.a")

 ELSEIF(WIN32)

   SET(LEMON_LIB_NAME "lemon.lib")

 ENDIF(UNIX)

 SET(LEMON_LIBRARY "@CMAKE_INSTALL_PREFIX@/lib/${LEMON_LIB_NAME}" CACHE FILEPATH "LEMON library")

 SET(LEMON_LIBRARIES "${LEMON_LIBRARY}")

 MARK_AS_ADVANCED(LEMON_LIBRARY LEMON_INCLUDE_DIR)