0.1.1:
 * improve UI responsiveness while computing previewing
 * use the correct icon theme in more cases
 * don't allow closing the window while running
 * make the 'Run' button insensitive while running
 * headings for added file and field sources
 * update the preview after running
 * remove created directories when rolling back a failed rename
 * bug: run stops working after running with duplicate field names
 * bug: fails when moving a file to itself
 * bug: incorrect tab order for dynamic widgets
 * bug: install process misses SVG icon

0.1.0:
 * first release