explicitly require threading library for executables that need to be linked to it
added cmake scripts to find packages needed for conversion to LCIO and integration into EUTelescope
added native reader library based on code from EUTelescope;
if enabled using BUILD_nreader and as long as EUTelescope and ILCSoft packages can be found (e.g. after sourcing EUTel's build_env.sh script) the shared library is built and installed in ./lib/libNativeReader.so;
when added to MARLIN_DLL environment variable, this makes the processor 'EUTelNativeReader' available within Marlin.
This library makes the NativeReader processor within EUTelescope obsolete and resolve the circular dependence between the packages