Added Lemon graph algorithms library cmake finder.

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@16109 383ad7c9-94d9-4d36-a494-682f7c89f535

cmake/FindLemon.cmake

+# - Try to find LEMON
+# Once done this will define
+#  LEMON_FOUND - System has Lemon
+#  LEMON_INCLUDE_DIRS - The Lemon include directories
+#  LEMON_LIBRARIES - The libraries needed to use Lemon
+
+if (LEMON_INCLUDE_DIR)
+  # in cache already
+  set(LEMON_FOUND TRUE)
+  set(LEMON_INCLUDE_DIRS "${LEMON_INCLUDE_DIR}" )
+  set(LEMON_LIBRARIES "${LEMON_LIBRARY}" )
+else (LEMON_INCLUDE_DIR)
+
+find_path(LEMON_INCLUDE_DIR 
+          NAMES lemon/min_cost_arborescence.h
+          PATHS "$ENV{LEMON_HOME}/include"
+          		  "~/sw/lemon/include"
+                  "/Library/lemon/mac64/include"
+                  "/Library/lemon/include"
+                 "C:\\libs\\lemon\\include"
+          )
+
+find_library(LEMON_LIBRARY 
+             NAMES libemon.a
+             PATHS "$ENV{LEMON_HOME}/lib"
+             	   "~/sw/lemon/lib"
+                   "/Library/lemon/mac64/lib"
+                   "C:\\libs\\lemon\\lib"
+             )
+
+set(LEMON_INCLUDE_DIRS "${LEMON_INCLUDE_DIR}" )
+set(LEMON_LIBRARIES "${LEMON_LIBRARY}" )
+
+message("Found lemon include directory: " ${LEMON_INCLUDE_DIR})
+message("Found lemon library: " ${LEMON_LIBRARY})
+
+endif(LEMON_INCLUDE_DIR)