Add module to find gnuplot

Modules/Documentation.cmake

@@ -16,6 +16,7 @@ IF (BUILD_DOCUMENTATION)
   #
   INCLUDE(${CMAKE_ROOT}/Modules/FindUnixCommands.cmake)
   INCLUDE(${CMAKE_ROOT}/Modules/FindDoxygen.cmake)
+  INCLUDE(${CMAKE_ROOT}/Modules/FindGnuplot.cmake)
   INCLUDE(${CMAKE_ROOT}/Modules/FindHhc.cmake)
   INCLUDE(${CMAKE_ROOT}/Modules/FindPerl.cmake)
   INCLUDE(${CMAKE_ROOT}/Modules/FindWget.cmake)

Modules/FindGnuplot.cmake

@@ -0,0 +1,21 @@
+# 
+# this module looks for gnuplot
+#
+
+INCLUDE(${CMAKE_ROOT}/Modules/FindCygwin.cmake)
+
+FIND_PROGRAM(GNUPLOT
+  NAMES 
+  gnuplot
+  pgnuplot
+  wgnupl32
+  PATH
+  ${CYGWIN_INSTALL_PATH}/bin
+  /bin
+  /usr/bin 
+  /usr/local/bin
+  /sbin
+)
+MARK_AS_ADVANCED(
+  GNUPLOT
+)