[CMake] Stops linking Boost_LIBRARIES by default (Fixes FS#1312)

Previously, when adding boost flags, we always linked all
Boost_LIBRARIES. At least for the core modules this not needed
and resulted in errors on some systems.

This patch changes the add_dune_boost_flags function. By default no
libraries are linked, but one can either provide the libraries using
the LIBRARIES option or request linkage of all boost libraries with
the LINK_ALL_BOOST_LIBRARIES option.

cmake/modules/DuneBoost.cmake

 # Searches for boost and provides the following function:
 #
-# add_dune_boost_flags(targets)
+# add_dune_boost_flags(targets [LINK_ALL_BOOST_LIBRARIES]
+#                      LIBRARIES lib1 lib2 ...)
 #
 # Adds boost compiler flags and libraries, and activates
-# Boost for the specified targets.
+# Boost for the specified targets. Libraries can either be
+# provided by listing them after the LIBRARIES keyword or one
+# can request linking with all available boost libraries by
+# passing the LINK_ALL_BOOST_LIBRARIES option to the function
+# call.
 find_package(Boost)
 set(HAVE_DUNE_BOOST ${Boost_FOUND})
 
 function(add_dune_boost_flags _targets)
+  cmake_parse_arguments(DUNE_BOOST LINK_ALL_BOOST_LIBRARIES "" LIBRARIES ${ARGN})
   if(Boost_FOUND)
     include_directories("${Boost_INCLUDE_DIRS}")
     foreach(_target ${_targets})
-      target_link_libraries(${_target} ${Boost_LIBRARIES})
+      if(DUNE_BOOST_LINK_ALL_BOOST_LIBRARIES)
+	target_link_libraries(${_target} "${DUNE_Boost_LIBRARIES}")
+      else(DUNE_BOOST_LINK_ALL_BOOST_LIBRARIES)
+	target_link_libraries(${_target} "${DUNE_BOOST_LIBRARIES}")
+      endif(DUNE_BOOST_LINK_ALL_BOOST_LIBRARIES)
       # The definitions are a hack as we do not seem to know which MPI implementation was
       # found.
       GET_TARGET_PROPERTY(_props ${_target} COMPILE_FLAGS)