config: refactorize
bluez-agent: remove --adapter option

Now provided by btts-config-adapter. (Actually the option was ignored
here.)
bluez-pairing-tool: remove --adapter option

Now provided by btts-config-adapter.
bluez-agent: Implement proper CLI + fix bugs
bluez-pairing-tool: Implement proper CLI
bluez-pairing-tool: Add expect-state command
Extract cliutils
device: Initial commit
Extract 'config powered' as 'adapter powered'
Rename 'bluez-agent' to 'agent'
Rename 'bluez-pairing-tool' to 'pairing'
Refactorize 'config profiles' to 'a2dp' and 'hfp'
adapter discoverable: Initial commit
Add --expect option
agent: Add expect-* commands
config host-alias: Initial commit
rpc: Initial commit