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.

AM_CXXFLAGS = $(WARNINGCXXFLAGS)

AM_CPPFLAGS = -I$(top_srcdir) -I$(top_builddir)

LDADD = $(top_builddir)/lemon/libemon.la

EXTRA_DIST = \

	CMakeLists.txt \

	digraph.lgf

noinst_PROGRAMS = \

	arg_parser_demo \

	graph_to_eps_demo \

	lgf_demo

arg_parser_demo_SOURCES = arg_parser_demo.cc

graph_to_eps_demo_SOURCES = graph_to_eps_demo.cc

lgf_demo_SOURCES = lgf_demo.cc