gitk: Persist config for ignore space and diff mode

Save the user's choice for "Ignore space change: and diff mode so they don't have to adjust these options every time they open Gitk if the defaults don't work for them.

Signed-off-by: Teddy Zhang <lostindark@gmail.com>

Author: lostindark

gitk

@@ -2668,7 +2668,6 @@ proc makewindow {} {
         -command changeignorespace -variable ignorespace
     pack .bleft.mid.ignspace -side left -padx 5
 
-    set worddiff [mc "Line diff"]
     makedroplist .bleft.mid.worddiff worddiff [mc "Line diff"] \
         [mc "Markup words"] [mc "Color words"]
     trace add variable worddiff write changeworddiff
@@ -12594,7 +12593,7 @@ set diffbgcolors {"#fff3f3" "#f0fff0"}
 set diffcontext 3
 set mergecolors {red blue "#00ff00" purple brown "#009090" magenta "#808000" "#009000" "#ff0080" cyan "#b07070" "#70b0f0" "#70f0b0" "#f0b070" "#ff70b0"}
 set ignorespace 0
-set worddiff ""
+set worddiff [mc "Line diff"]
 set markbgcolor "#e0e0ff"
 
 set headbgcolor "#00ff00"
@@ -12675,6 +12674,7 @@ set config_variables {
     headfgcolor
     headoutlinecolor
     hideremotes
+    ignorespace
     indexcirclecolor
     kscroll
     limitdiffs
@@ -12708,6 +12708,7 @@ set config_variables {
     uifont
     visiblerefs
     web_browser
+    worddiff
     workingfilescirclecolor
     wrapcomment
     wrapdefault