[Enhancement] Resizing symbol with right aligned text
At the moment, symbol instances are always resized from the top-left.

However, if the widest text layer is right aligned, it would be better if the symbol instance resized from the right, instead of the left.

Example of current behaviour:
![2018-02-11 20 19 44](https://user-images.githubusercontent.com/6570446/36071830-08b9a752-0f69-11e8-8f2a-716e2fc42da7.gif)
