Support negative costs and bounds in NetworkSimplex (#270)

* The interface is reworked to support negative costs and bounds.
- ProblemType and problemType() are renamed to
SupplyType and supplyType(), see also #234.
- ProblemType type is introduced similarly to the LP interface.
- 'bool run()' is replaced by 'ProblemType run()' to handle
unbounded problem instances, as well.
- Add INF public member constant similarly to the LP interface.
* Remove capacityMap() and boundMaps(), see also #266.
* Update the problem definition in the MCF module.
* Remove the usage of Circulation (and adaptors) for checking feasibility.
Check feasibility by examining the artifical arcs instead (after solving
the problem).
* Additional check for unbounded negative cycles found during the
algorithm (it is possible now, since negative costs are allowed).
* Fix in the constructor (the value types needn't be integer any more),
see also #254.
* Improve and extend the doc.
* Rework the test file and add test cases for negative costs and bounds.

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