The specified child already has a parent

[arturbryzhatyi]

Hi! First of all thx for your great library!

There is one issue in your library:
For example, we show tooltip from button1. If user taps on button1 twice or more, application will crash, because ViewTooltip didn't remove tooltip_view from it's parent before.

Row 87, ViewTooltip.java

[florent37]

create a new ViewTooltip at each click