Renamed CMAKE_(SOURCE|BINARY)_DIR to PROJECT_(SOURCE|BINARY)_DIR to let people...

Renamed CMAKE_(SOURCE|BINARY)_DIR to PROJECT_(SOURCE|BINARY)_DIR to let people build dune modules as subproject of another project.

[[Imported from SVN: r1791]]

CMakeLists.txt

@@ -7,7 +7,7 @@ cmake_minimum_required(VERSION 2.8.6)
 #find dune-common and set the module path
 find_package(dune-common)
 list(APPEND CMAKE_MODULE_PATH ${dune-common_MODULE_PATH}
-  "${CMAKE_SOURCE_DIR}/cmake/modules")
+  "${PROJECT_SOURCE_DIR}/cmake/modules")
 
 #include the dune macros
 include(DuneMacros)