Text input position is not reset correctly

[jansol]

Amidst the tomfoolery involved in confirming that #1157 is fixed, I noticed a couple of other problems:

1. Typing something longer than the window width will cause the candidate window to go outside of the Tauon window instead of scrolling the input string to keep the cursor and candidate window in view
2. Upon application startup, when leaving the global search etc, the IME input position is not reset to the top left where the cursor would appear for global search. Instead it will start from an undefined initial position on launch or from the last known position after leaving search (which can be off screen due to 1.)