Executables append omnitrace library directory to LD_LIBRARY_PATH (#356)

- omnitrace-run, omnitrace-sample, and omnitrace-causal now automatically append the LD_LIBRARY_PATH with the directory containing the omnitrace libraries
  - this helps ensure that binary rewritten exes can resolve omnitrace-rt library location

source/bin/omnitrace-run/impl.cpp

@@ -191,6 +191,7 @@ prepare_environment_for_run(parser_data_t& _data)
     if(_data.launcher.empty())
     {
         omnitrace::argparse::add_ld_preload(_data);
+        omnitrace::argparse::add_ld_library_path(_data);
     }
 }