CMake: Consolidate python dependencies into a single Find module

Fixes #222

cmake/FindPythonFull.cmake

+#------------------------------------------------------------------------------#
+# Distributed under the OSI-approved Apache License, Version 2.0.  See
+# accompanying file Copyright.txt for details.
+#------------------------------------------------------------------------------#
+#
+# PythonFull
+# -----------
+#
+# Try to find various pieces needed for a full python environment including
+# python libs, interpreter, and modules
+#
+# This module defines the following variables:
+#
+#   PythonFull_FOUND
+#   PYTHONINTERP_FOUND
+#   PYTHON_EXECUTABLE
+#   PYTHONLIBS_FOUND
+#   PYTHON_LIBRARIES
+#   PythonModule_${module_NAME}_FOUND
+#   
+# This is intented to be called by specifying components for libraries,
+# interpreter, and modules.  So, for example, if you needed libraries, the
+# interpreter, mpi4py, and numpy then you would call:
+#
+#   find_package(PythonFull COMPONENTS Interp Libs mpi4py numpy)
+#
+
+include(CMakeFindDependencyMacro)
+set(_req_vars)
+foreach(comp IN LISTS PythonFull_FIND_COMPONENTS)
+  if(comp STREQUAL Interp)
+    find_package(PythonInterp)
+    set(PythonFull_${comp}_FOUND ${PYTHONINTERP_FOUND})
+    list(APPEND _req_vars PYTHON_EXECUTABLE)
+  elseif(comp STREQUAL Libs)
+    find_package(PythonLibsNew)
+    set(PythonFull_${comp}_FOUND ${PYTHONLIBS_FOUND})
+    list(APPEND _req_vars PYTHON_LIBRARIES)
+  else()
+    # Parse off any specified headers and libs for a given module
+    set(_comp ${comp})
+    list(GET _comp 0 _mod)
+    string(REGEX REPLACE "${_mod}\\\;[^;]*" "${_mod}"
+      PythonFull_FIND_COMPONENTS "${PythonFull_FIND_COMPONENTS}"
+    )
+    set(PythonFull_FIND_REQUIRED_${_mod} TRUE)
+    find_package(PythonModule COMPONENTS ${_comp})
+    set(PythonFull_${_mod}_FOUND ${PythonModule_${_mod}_FOUND})
+  endif()
+endforeach()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(PythonFull
+  REQUIRED_VARS ${_req_vars}
+  HANDLE_COMPONENTS
+)

cmake/FindPythonModule.cmake

@@ -119,8 +119,9 @@ set( PythonModule_${module_NAME}_PATH
   endif()
 
   include(FindPackageHandleStandardArgs)
-  find_package_handle_standard_args(PythonModule_${module_NAME} DEFAULT_MSG
-    ${required_vars}
+  find_package_handle_standard_args(PythonModule_${module_NAME}
+    FOUND_VAR PythonModule_${module_NAME}_FOUND
+    REQUIRED_VARS ${required_vars}
   )
 endif()