User Interface improvements

This project aims at improving Synfig’s GUI by implementing new features which are available at other related applications but not at Synfig yet. Along with other UI fixes and introducements to enhance the user experience, artist workflow, and efficiency. The user interface of any application is one of the most noticeable areas to both new users and old ones. An application's UI can make or break its usability. Therefore, the goal in mind is that by the end of this project these new features implemented will ease and visibly enhance the process of animating for synfig users.The main features to be included: These features form the core of this UI enhancement project - Add the possibility to change parameters using the mouse - Ctrl + tab to switch tabs - Shortcuts for switching between animation windows - Show/Hide rulers - Search functionality in parameters panel - Better way to set playback area - Add ability to copy/paste waypoints Additional features : - Allow rotation of guides in canvas - Faster entry of values in value fields - Reducing float precision displayed in parameters values - Fixing inconsistent look of parameter value spin button when expanded - Appropriate adjustment of “paragraph text dialog” size