Allow to hide popup-buttons panel

[alextrs]

Hello,

We want to be able to use our own set of buttons in popup, but currently $ionicPopup adds panel for buttons even if there are no buttons at all. We need it so we can conditionally disable / enable / hide / show buttons. Looks like it should be very minor change (not sure about backward compatibility)

Thank you,
Aliaks

[drewrygh]

Confirmed, <div class='popup-buttons'> wrapper should be removed if no buttons are used. Thanks.

[drewrygh]

Just noticed this is a duplicate of #2344. You can follow the progress in that issue thread. Thanks!

[ionitron-bot]

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