Merge branch 'master' of https://github.com/j6t/gitk

* 'master' of https://github.com/j6t/gitk: gitk: introduce support for the Meson build system gitk: extract script to build executable gitk: make the "list references" default window width wider gitk: fix arrow keys in input fields with Tcl/Tk >= 8.6 gitk: Use an external icon file on Windows gitk: Unicode file name support gitk(Windows): avoid inadvertently calling executables in the worktree