gitk: prefs dialog: refine Auto-select UI

Tl;DR: change Auto-select text, move the length input to a new line.

The Auto-select preference auto-selects [part of] the commit ID text
at the respective widget on startup, and when the current commit at
the graph changes.

Its real premise, however, is to populate the selection clipboard
with the commit ID. Consider, for instance, how meaningless it is on
platforms without a selection clipboard - like Windows or macOS (on
Windows the selection is not even visible with the default Tk theme,
because it's only visible in focused widgets - which the commit ID
widget is not during normal application of this selection).

So rename the Auto-select label to "Copy commit ID to X11 selection",
to reflect better the ultimate outcome of its application

Note that there exists other, non-X11 platforms with a selection
clipboard, like Wayland, and if a native Tk client exists on such
platforms, then the description will not be accurate, but hopefully
it's not too misleading either.

Additionally, move the length input widget to a new line, because:
- This length applies to both Auto-select and "Copy commit reference"
  context menu item, so it's not exclusive to the selection length.
- The next commit will add support for primary clipboard as well,
  where this length will also be used.

Also, move the "Hide remotes" item above these selection prefs, to
keep the selection prefs semi-grouped before the spacing of the
following title "Diff display options".

Signed-off-by: Avi Halachmi (:avih) <[email protected]>

Author: avih

gitk

@@ -11594,14 +11594,17 @@ proc prefspage_general {notebook} {
     ${NS}::checkbutton $page.showlocal -text [mc "Show local changes"] \
         -variable showlocalchanges
     grid x $page.showlocal -sticky w
-    ${NS}::checkbutton $page.autoselect -text [mc "Auto-select commit ID (length)"] \
-        -variable autoselect
-    spinbox $page.autosellen -from 1 -to 40 -width 4 -textvariable autosellen
-    grid x $page.autoselect $page.autosellen -sticky w
     ${NS}::checkbutton $page.hideremotes -text [mc "Hide remote refs"] \
         -variable hideremotes
     grid x $page.hideremotes -sticky w
 
+    ${NS}::checkbutton $page.autoselect -text [mc "Copy commit ID to X11 selection"] \
+        -variable autoselect
+    grid x $page.autoselect -sticky w
+    spinbox $page.autosellen -from 1 -to 40 -width 4 -textvariable autosellen
+    ${NS}::label $page.autosellenl -text [mc "Length of commit ID to copy"]
+    grid x $page.autosellenl $page.autosellen -sticky w
+
     ${NS}::label $page.ddisp -text [mc "Diff display options"]
     grid $page.ddisp - -sticky w -pady 10
     ${NS}::label $page.tabstopl -text [mc "Tab spacing"]