Aliases support (inspired by git)

[arikon]

One could define alias as cb = create -b and invoke bem cb block. COA should resolve cb alias and invoke bem create -b block command.

Also think of shell completion for aliases.

[tadatuta]

it'd also be great to have possibility to add aliases for options like

.opt()
    .name('noCache')
    .title('drop cache before running make')
    .short('n')
    .short('f') // alias for n
    .long('no-cache')
    .long('force') // alias for no-cache
    .flag()
    .end()