Slightly modify the interface of Circulation and Preflow (#266)
in order to synchronize them to the interface of NetworkSimplex.

Circulation:
- The "delta" notation is replaced by "supply".
- lowerCapMap(), upperCapMap() are renamed to lowerMap() and upperMap().
- Value is renamed to Flow.

Preflow:
- Value is renamed to Flow.

 prefix=@prefix@

 exec_prefix=@exec_prefix@

 libdir=@libdir@

 includedir=@includedir@

 Name: @PACKAGE_NAME@

 Description: Library of Efficient Models and Optimization in Networks

 Version: @PACKAGE_VERSION@

 Libs: -L${libdir} -lemon

 Cflags: -I${includedir}