[pts-core] Calling function that doesn't exist.

in generate_download_file_lists(), it calls "generate_download_files_list()" from test_install_request, which does not exist in pts_test_install_request. I have replaced it with the proper function, generate_download_object_list().
[pts-core] Fixed incorrect variable name.
[pts-core] Fixed incorrect variable names.
[pts-core] Added error message on failed installation in webui.

In webui, if a test fails to install, it will continue running the test because it does not run an initial check on the test run manager. I have fixed it so that run_benchmark ends if the check fails, and to send an error message to the web interface.
Merge branch 'master' of https://github.com/phoronix-test-suite/phoronix-test-suite
Merge pull request #6 from NickZ/master

Added error message on failed installation in webui.