Print Python version

- And add message if interpreter not found
- Remove the QUIET to get some idea of what cmake is doing
- Trying to debug issue on Appveyor
diff --git a/build/cmake/DefineOptions.cmake b/build/cmake/DefineOptions.cmake
index 3584b5f..928e19b 100644
--- a/build/cmake/DefineOptions.cmake
+++ b/build/cmake/DefineOptions.cmake
@@ -121,7 +121,7 @@
     COMPONENTS
         Interpreter # for Python executable
         Development # for Python.h
-    QUIET)
+    )
 CMAKE_DEPENDENT_OPTION(BUILD_PYTHON "Build Python library" ON
                        "BUILD_LIBRARIES;WITH_PYTHON;Python3_Interpreter_FOUND;Python3_Development_FOUND" OFF)
 
@@ -209,7 +209,11 @@
 message(STATUS)
 message(STATUS "  Build Python library:                       ${BUILD_PYTHON}")
 MESSAGE_DEP(WITH_PYTHON "Disabled by WITH_PYTHON=OFF")
+MESSAGE_DEP(Python3_Interpreter_FOUND "Python interpreter missing")
 MESSAGE_DEP(Python3_Development_FOUND "Python libraries missing")
+if(BUILD_PYTHON)
+    message(STATUS "    Version:                                  ${Python3_VERSION}")
+endif()
 if(MSVC)
     message(STATUS "  Using static runtime library:               ${WITH_MT}")
 endif(MSVC)