Fully customizable window size for SmallTime

Although I have to attend to many tasks with highier priority, I managed to finish the main window size customisation for SmallTime. The custom window width handle was removed and window resizing is now handled directly by the operating system. Right now everything seems to run smoothly.Text size transitions are not 100% smooth when the user creates many tasks, which is not a deal-breaker but I will have to look into it after the 1.8.9 release.

That being said, the next version will probably not be released this year because of my time constraints and the fact that the full window-size customization is a big change that could have unforeseen consequences that would be revealed after some time of active usage.

Meanwhile, I have prepared a prototype of a new SmallSkill Studio website, which will allow me to implement a broad set of features in the future. More about this troughtout the next year.