hgk: support the old way of getting the current Ttk theme (issue3808) It seems like the API has changed somewhere around 8.5.7, so the preferred way of getting the current theme is now [ttk::style theme use], while the deprecated (but still working) is $::ttk::currentTheme.

addremove: don't perform m.exact/rel until needed Moves the m.exact and m.rel calls within the conditionals they are used in. On a large repo this brings addremove from 7.1 seconds down to 6.3 (13%).