Fix netgen executable and library RUNPATHs

netgen defaults to the CMAKE_INSTALL_RPATH, which includes "$ORIGIN",
i.e. the BINDIR, but it should only point to the library directories.

The libraries are all located in the same directory, so just use "$ORIGIN"
for these.

Author: StefanBruens

CMakeLists.txt

@@ -207,7 +207,8 @@ set(NG_INSTALL_DIR EXPORT netgen-targets RUNTIME DESTINATION ${NG_INSTALL_DIR_BI
 install(EXPORT netgen-targets DESTINATION ${NG_INSTALL_DIR_CMAKE} COMPONENT netgen_devel)
 
 set(CMAKE_MACOSX_RPATH TRUE)
-set(CMAKE_INSTALL_RPATH "${NG_RPATH_TOKEN};${NG_RPATH_TOKEN}/${NETGEN_RPATH}")
+# Default RPATH used for all libraries
+set(CMAKE_INSTALL_RPATH "${NG_RPATH_TOKEN}")
 if(BUILD_FOR_CONDA)
     file(RELATIVE_PATH py_rpath "/bin" "/${NG_INSTALL_DIR_LIB}")
     set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_RPATH};${py_rpath}")

ng/CMakeLists.txt

@@ -24,6 +24,7 @@ if(USE_GUI)
       target_sources(netgen PRIVATE ../windows/netgen.rc)
     endif(WIN32)
     target_link_libraries( netgen nglib nggui netgen_python netgen_gui)
+    set_target_properties( netgen PROPERTIES INSTALL_RPATH "${NG_RPATH_TOKEN}/${NETGEN_RPATH}")
     install(TARGETS netgen ${NG_INSTALL_DIR})
     if(APPLE)
         set_target_properties(netgen PROPERTIES OUTPUT_NAME netgen)