Change quick_add_keys_to_file to being a script through an entry point in setup.py

This allows for easier testing of command line parsing logic and begins to address #97
Move script_helpers into same directory was the scripts
Fix relative import
Add entry point for quick_add_keys_to_file
Convert run_patch to a console_script entry_point

Addresses #97
Add attempt to provide a common doctoring for main function in script docstrings
Convert run_astrometry to a console_script entry_point

Addresses #97