use canonical cmake procedure to link selected boost components

* this fixes the issue of a missing rpath to the shared objects

CMakeLists.txt

 cmake_minimum_required(VERSION 2.6)
+
 project(BioEM)
 
+###use g++ and gcc instead of c++ and cc
+
+##this works but would change the default cmake toolchain precedence c++,g++,...
+#if (NOT (CMAKE_CXX_COMPILER OR $ENV{CXX}))
+#    set (CMAKE_CXX_COMPILER g++)
+#endif()
+
+##this works but would change the default cmake toolchain precedence cc,gcc,...
+#if (NOT (CMAKE_C_COMPILER OR $ENV{CC}))
+#    set (CMAKE_C_COMPILER gcc)
+#endif()
+
 ###Set up options
 option (USE_CUDA "Build BioEM with CUDA support" OFF)
 option (USE_OPENMP "Build BioEM with OpenMP support" ON)
@@ -8,6 +21,7 @@ option (USE_MPI "Build BioEM with MPI support" ON)
 option (PRINT_CMAKE_VARIABLES "List all CMAKE Variables" OFF)
 option (CUDA_FORCE_GCC "Force GCC as host compiler for CUDA part (If standard host compiler is incompatible with CUDA)" ON)
 
+
 ###Set up general variables
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}")
@@ -35,8 +49,10 @@ if (NOT FFTW_FOUND)
 endif()
 include_directories(${FFTW_INCLUDE_DIRS})
 
-find_package(Boost 1.43 REQUIRED)
-include_directories(${Boost_INCLUDE_DIRS})
+find_package( Boost 1.43 REQUIRED COMPONENTS program_options )
+include_directories( ${Boost_INCLUDE_DIRS} )
+
+
 
 ###Find Optional Packages
 
@@ -127,7 +143,7 @@ if (FFTWF_LIBRARIES)
 else()
         target_link_libraries(bioEM -L${FFTW_LIBDIR} -lfftw3 -lfftw3f)
 endif()
-target_link_libraries(bioEM -L${Boost_LIBRARY_DIRS} -lboost_program_options)
+target_link_libraries(bioEM ${Boost_PROGRAM_OPTIONS_LIBRARY})
 
 if (MPI_FOUND)
         target_link_libraries(bioEM ${MPI_LIBRARIES})
@@ -150,4 +166,3 @@ if (PRINT_CMAKE_VARIABLES)
                 message(STATUS "${_variableName}=${${_variableName}}")
         endforeach()
 endif()
-