[text] fix problems with scrolling interaction
[text] fix problems with scrolling interaction

The cursor x position is already translated, so we do not need to take the
actors allocation into account when calculating scrolling.

Additionally, we need to update the text_x value before running
clutter_text_ensure_cursor_position.

djdeath/clutter,djdeath/clutter-multithreaded,djdeath/clutter-android,djdeath/clutter,rkudiyarov/clutter_osx,GNOME/clutter,kerrickstaley/clutter-vala,djdeath/clutter-android,Distrotech/clutter,djdeath/clutter-multithreaded,djdeath/clutter-multithreaded,heysion/clutter-clone,nobled/clutter,jigpu/clutter,spatulasnout/clutter,rkudiyarov/clutter_osx,tardyp/clutter,kerrickstaley/clutter-vala,djdeath/clutter-android,Distrotech/clutter,djdeath/clutter-android,collects/clutter,ebassi/clutter,rkudiyarov/clutter_osx,nobled/clutter,spatulasnout/clutter,heysion/clutter-clone,dlespiau/clutter,dlespiau/clutter,spatulasnout/clutter,djdeath/clutter,Distrotech/clutter,ebassi/clutter,jigpu/clutter,kerrickstaley/clutter-vala,djdeath/clutter,jigpu/clutter,GNOME/clutter,ebassi/clutter,kerrickstaley/clutter-vala,jigpu/clutter,djdeath/clutter-android,GNOME/clutter,djdeath/clutter-multithreaded,djdeath/clutter,djdeath/clutter,dlespiau/clutter,ebassi/clutter,tardyp/clutter,spatulasnout/clutter,jigpu/clutter,heysion/clutter-clone,heysion/clutter-clone,collects/clutter,nobled/clutter,collects/clutter,heysion/clutter-clone,Distrotech/clutter,GNOME/clutter,tardyp/clutter,jigpu/clutter,collects/clutter,rkudiyarov/clutter_osx,collects/clutter,Distrotech/clutter,ebassi/clutter,spatulasnout/clutter,Distrotech/clutter,GNOME/clutter