Created by: dpursehouse
Summary: when the bash_completion script is loaded, the user can use the tab key to automatically complete the name of the buck command, or if there are multiple commands beginning with the same letter(s) suggest commands to use.
Test:
Install the completion script:
$ ./scripts/bash_completion
Suggestion of all available commands:
$ buck audit build cache clean install project targets test uninstall
Suggestion of available commands with given starting letter:
$ buck c cache clean
Completion of command with given starting letter
$ buck b
("b" is auto-completed to "build")
Change-Id: I573808900811ed79733895f34cccb388535c80b0