Use OPM_MACROS_ROOT to locate build scripts

By using a separate variable for this we can easily grep for where
the build system depends on its own location, and also change the
policy regarding this later.

Note that there is no opm-macros module; this is a "psuedo"-module
which links to an additional one (currently, the one we're in)

cmake/Modules/DuneCompat.cmake

@@ -17,7 +17,7 @@ if (CMAKE_GENERATOR MATCHES "Unix Makefiles")
   # amazingly, nothing depends on the generated Makefile, so this can be
   # run whenever in the build without trigging a compile of e.g. config.h
   add_custom_target (dune-compat ALL
-	COMMAND ${CMAKE_COMMAND} -DCMAKE_HOME_DIRECTORY=${CMAKE_HOME_DIRECTORY} -P ${PROJECT_SOURCE_DIR}/cmake/Scripts/DuneCompat2.cmake
+	COMMAND ${CMAKE_COMMAND} -DCMAKE_HOME_DIRECTORY=${CMAKE_HOME_DIRECTORY} -P ${OPM_MACROS_ROOT}/cmake/Scripts/DuneCompat2.cmake
 	COMMENT "Patching Makefile to be DUNE compatible"
 	)
 endif (CMAKE_GENERATOR MATCHES "Unix Makefiles")

cmake/Modules/LibtoolArchives.cmake

@@ -141,7 +141,7 @@ function (configure_la name target)
   # assume that we are in cmake/Modules, and that the template have been
   # put in cmake/Templates. we cannot use CMAKE_CURRENT_LIST_DIR because
   # this is in a function, and we cannot know who's calling us
-  set (templ_dir "${PROJECT_SOURCE_DIR}/cmake/Templates")
+  set (templ_dir "${OPM_MACROS_ROOT}/cmake/Templates")
 
   
   # only write an .la if libtool is found; otherwise we have no use

cmake/Modules/OpmDistClean.cmake

@@ -68,7 +68,7 @@ macro (opm_dist_clean opm)
 	  )
   endif (NOT PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
   # script to remove empty directories (can't believe this isn't included!)
-  set (rmdir "${PROJECT_SOURCE_DIR}/cmake/Scripts/RemoveEmptyDir.cmake")
+  set (rmdir "${OPM_MACROS_ROOT}/cmake/Scripts/RemoveEmptyDir.cmake")
   add_custom_target (distclean
 	COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR} -- clean
 	COMMAND ${CMAKE_COMMAND} -E remove -f ${DISTCLEAN_FILES}

cmake/Modules/OpmDoc.cmake

@@ -13,7 +13,7 @@
 
 macro (opm_doc opm doxy_dir)
   # combine the template with local customization
-  file (READ ${PROJECT_SOURCE_DIR}/cmake/Templates/Doxyfile _doxy_templ)
+  file (READ ${OPM_MACROS_ROOT}/cmake/Templates/Doxyfile _doxy_templ)
   string (REPLACE ";" "\\;" _doxy_templ "${_doxy_templ}")
   if (EXISTS ${PROJECT_SOURCE_DIR}/${doxy_dir}/Doxylocal)
 	file (READ ${PROJECT_SOURCE_DIR}/${doxy_dir}/Doxylocal _doxy_local)

cmake/Modules/OpmLibMain.cmake

@@ -17,17 +17,17 @@
 # include special
 if (CMAKE_VERSION VERSION_LESS "2.8.3")
 	message (STATUS "Enabling compatibility modules for CMake 2.8.3")
-	list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules/compat-2.8.3")
+	list (APPEND CMAKE_MODULE_PATH "${OPM_MACROS_ROOT}/cmake/Modules/compat-2.8.3")
 endif (CMAKE_VERSION VERSION_LESS "2.8.3")
 
 if (CMAKE_VERSION VERSION_LESS "2.8.5")
 	message (STATUS "Enabling compatibility modules for CMake 2.8.5")
-	list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules/compat-2.8.5")
+	list (APPEND CMAKE_MODULE_PATH "${OPM_MACROS_ROOT}/cmake/Modules/compat-2.8.5")
 endif (CMAKE_VERSION VERSION_LESS "2.8.5")	
 
 if (CMAKE_VERSION VERSION_LESS "2.8.7")
 	message (STATUS "Enabling compatibility modules for CMake 2.8.7")
-	list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules/compat-2.8.7")
+	list (APPEND CMAKE_MODULE_PATH "${OPM_MACROS_ROOT}/cmake/Modules/compat-2.8.7")
 endif (CMAKE_VERSION VERSION_LESS "2.8.7")
 
 # don't write default flags into the cache, preserve that for user set values

cmake/Modules/OpmProject.cmake

@@ -70,7 +70,7 @@ function (opm_cmake_config name)
   # assume that the template is located in cmake/Templates (cannot use
   # the current directory since this is in a function and the directory
   # at runtime not at definition will be used
-  set (template_dir "${PROJECT_SOURCE_DIR}/cmake/Templates")
+  set (template_dir "${OPM_MACROS_ROOT}/cmake/Templates")
 
   # write configuration file to locate library
   configure_cmake_file (${name} "config" "")

cmake/Modules/UseVersion.cmake

@@ -39,7 +39,7 @@ else ()
 	  -DPROJECT_SOURCE_DIR=${PROJECT_SOURCE_DIR}
 	  -DPROJECT_BINARY_DIR=${PROJECT_BINARY_DIR}
 	  -DPROJECT_LABEL=${${project}_LABEL}
-	  -P ${PROJECT_SOURCE_DIR}/cmake/Scripts/WriteVerSHA.cmake
+	  -P ${OPM_MACROS_ROOT}/cmake/Scripts/WriteVerSHA.cmake
 	  COMMENT "Updating version information"
 	  )