phpbrew completion for bash featuring:

- phpbrew [tab tab]
- phpbrew use|switch|clean|remove|purge [tab tab]
- phpbrew ext [tab tab]
- phpbrew ext install|disable|enable [tab tab]
- phpbrew help [tab tab]

TODO:

- `phpbrew install [tab tab]` completion for php versions and variants
enabled completion for `phpbrew download`