[cmake,release] Corrects setting of HAVE_* variables.

For generating the config.h file we use the HAVE_* variables instead
of the CMake ones *_FOUND, Unfortunately, we sometines to not set
HAVE_* to the value of the *_FOUND vriable but to its name. Usually
we only query whether these variable are set at all. While
this often (except for psurface) does not pose a problem, it is semantically
wrong. Therfore this patch fixes this.

Kudos to Ansgar for pointing to this problem.

cmake/modules/FindSuperLU.cmake

@@ -131,7 +131,7 @@ else(SUPERLU_FOUND)
 endif(SUPERLU_FOUND)
 
 # set HAVE_SUPERLU for config.h
-set(HAVE_SUPERLU SUPERLU_FOUND)
+set(HAVE_SUPERLU ${SUPERLU_FOUND})
 
 #add all superlu related flags to ALL_PKG_FLAGS, this must happen regardless of a target using add_dune_superlu_flags
 if(SUPERLU_FOUND)
@@ -139,4 +139,4 @@ if(SUPERLU_FOUND)
   foreach(dir ${SUPERLU_INCLUDE_DIRS})
     set_property(GLOBAL APPEND PROPERTY ALL_PKG_FLAGS "-I${dir}")
   endforeach()
-endif()
\ No newline at end of file
+endif()