[cmake] Guess location of dune-common.

[[Imported from SVN: r12692]]

CMakeLists.txt

 project("dune-elasticity" CXX)
 cmake_minimum_required(VERSION 2.8.6)
 
-find_package(dune-common)
+if(NOT (dune-common_DIR OR dune-common_ROOT))
+  string(REPLACE ${CMAKE_PROJECT_NAME} dune-common dune-common_DIR ${PROJECT_BINARY_DIR})
+endif()
+
+find_package(dune-common REQUIRED)
 list(APPEND CMAKE_MODULE_PATH ${dune-common_MODULE_PATH})
 include(DuneMacros)