Gpu autodetection

Fix for https://github.com/cooperative-computing-lab/cctools/issues/382

- Add `.` to search path when looking for `cctools_gpu_autodetect`
- List `cctools_gpu_autodetect` as a `transfer_input_file` for Condor.
- Reconstruct `cctools_gpu_autodetect` at execution site before executing `work_queue_worker` on other batch systems.