Add tooltips to show full file names from the tree-view. Contributed by @takase1121.
Introduce NagView to show warning dialog about unsaved files. Contributed by @takase1121.
Detect High-DPI displays on Linux using Xft.dpi entry from xrdb's output. Contributed by @daubaris with modifications by @franko.
Made animations independent of framerate, and added a config setting config.animation_rate for customizing the speed of animations. Contributed by @liquidev.
Made borders between tabs look cleaner. Contributed by @liquidev.
Fix problem with files using hard tabs.