Do not show hidden options

[derlin]

An option that is configured with hidden=True should not appear in the TUI.

Minimal example:

@tui()
@click.command()
@click.option("-f", "--foo", default=False, is_flag=True, hidden=False)
@click.option("-b", "--bar", default=False, is_flag=True, hidden=True)
def cli(foo, bar):
   pass

In the above, foo should appear, but bar shouldn't.

(By the way, keep up the good work, the fixes in 0.4.0 are awesome!)

[derlin]

Still no news on this one?

[gaby]

@daneah This is probably fixed by this PR #32

Nvmd, similar but not same field