git-gui: Refactor about dialog code into its own module

The about dialog is getting somewhat long in size and will probably
only get more complex as I try to improve upon its display.  As the
options dialog is even more complex than the about dialog we move
the about dialog into its own module to reduce the complexity of the
option dialog module.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

lib/about.tcl

+# git-gui about git-gui dialog
+# Copyright (C) 2006, 2007 Shawn Pearce
+
+proc do_about {} {
+	global appvers copyright oguilib
+	global tcl_patchLevel tk_patchLevel
+
+	set w .about_dialog
+	toplevel $w
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+
+	label $w.header -text [mc "About %s" [appname]] \
+		-font font_uibold
+	pack $w.header -side top -fill x
+
+	frame $w.buttons
+	button $w.buttons.close -text {Close} \
+		-default active \
+		-command [list destroy $w]
+	pack $w.buttons.close -side right
+	pack $w.buttons -side bottom -fill x -pady 10 -padx 10
+
+	label $w.desc \
+		-text "[mc "git-gui - a graphical user interface for Git."]\n$copyright" \
+		-padx 5 -pady 5 \
+		-justify left \
+		-anchor w \
+		-borderwidth 1 \
+		-relief solid
+	pack $w.desc -side top -fill x -padx 5 -pady 5
+
+	set v {}
+	append v "git-gui version $appvers\n"
+	append v "[git version]\n"
+	append v "\n"
+	if {$tcl_patchLevel eq $tk_patchLevel} {
+		append v "Tcl/Tk version $tcl_patchLevel"
+	} else {
+		append v "Tcl version $tcl_patchLevel"
+		append v ", Tk version $tk_patchLevel"
+	}
+
+	set d {}
+	append d "git wrapper: $::_git\n"
+	append d "git exec dir: [gitexec]\n"
+	append d "git-gui lib: $oguilib"
+
+	label $w.vers \
+		-text $v \
+		-padx 5 -pady 5 \
+		-justify left \
+		-anchor w \
+		-borderwidth 1 \
+		-relief solid
+	pack $w.vers -side top -fill x -padx 5 -pady 5
+
+	label $w.dirs \
+		-text $d \
+		-padx 5 -pady 5 \
+		-justify left \
+		-anchor w \
+		-borderwidth 1 \
+		-relief solid
+	pack $w.dirs -side top -fill x -padx 5 -pady 5
+
+	menu $w.ctxm -tearoff 0
+	$w.ctxm add command \
+		-label {Copy} \
+		-command "
+		clipboard clear
+		clipboard append -format STRING -type STRING -- \[$w.vers cget -text\]
+	"
+
+	bind $w <Visibility> "grab $w; focus $w.buttons.close"
+	bind $w <Key-Escape> "destroy $w"
+	bind $w <Key-Return> "destroy $w"
+	bind_button3 $w.vers "tk_popup $w.ctxm %X %Y; grab $w; focus $w"
+	wm title $w "About [appname]"
+	tkwait window $w
+}

lib/option.tcl

@@ -54,84 +54,6 @@ proc save_config {} {
 	}
 }
 
-proc do_about {} {
-	global appvers copyright oguilib
-	global tcl_patchLevel tk_patchLevel
-
-	set w .about_dialog
-	toplevel $w
-	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-
-	label $w.header -text [mc "About %s" [appname]] \
-		-font font_uibold
-	pack $w.header -side top -fill x
-
-	frame $w.buttons
-	button $w.buttons.close -text {Close} \
-		-default active \
-		-command [list destroy $w]
-	pack $w.buttons.close -side right
-	pack $w.buttons -side bottom -fill x -pady 10 -padx 10
-
-	label $w.desc \
-		-text "[mc "git-gui - a graphical user interface for Git."]\n$copyright" \
-		-padx 5 -pady 5 \
-		-justify left \
-		-anchor w \
-		-borderwidth 1 \
-		-relief solid
-	pack $w.desc -side top -fill x -padx 5 -pady 5
-
-	set v {}
-	append v "git-gui version $appvers\n"
-	append v "[git version]\n"
-	append v "\n"
-	if {$tcl_patchLevel eq $tk_patchLevel} {
-		append v "Tcl/Tk version $tcl_patchLevel"
-	} else {
-		append v "Tcl version $tcl_patchLevel"
-		append v ", Tk version $tk_patchLevel"
-	}
-
-	set d {}
-	append d "git wrapper: $::_git\n"
-	append d "git exec dir: [gitexec]\n"
-	append d "git-gui lib: $oguilib"
-
-	label $w.vers \
-		-text $v \
-		-padx 5 -pady 5 \
-		-justify left \
-		-anchor w \
-		-borderwidth 1 \
-		-relief solid
-	pack $w.vers -side top -fill x -padx 5 -pady 5
-
-	label $w.dirs \
-		-text $d \
-		-padx 5 -pady 5 \
-		-justify left \
-		-anchor w \
-		-borderwidth 1 \
-		-relief solid
-	pack $w.dirs -side top -fill x -padx 5 -pady 5
-
-	menu $w.ctxm -tearoff 0
-	$w.ctxm add command \
-		-label {Copy} \
-		-command "
-		clipboard clear
-		clipboard append -format STRING -type STRING -- \[$w.vers cget -text\]
-	"
-
-	bind $w <Visibility> "grab $w; focus $w.buttons.close"
-	bind $w <Key-Escape> "destroy $w"
-	bind $w <Key-Return> "destroy $w"
-	bind_button3 $w.vers "tk_popup $w.ctxm %X %Y; grab $w; focus $w"
-	wm title $w "About [appname]"
-	tkwait window $w
-}
-
 proc do_options {} {
 	global repo_config global_config font_descs
 	global repo_config_new global_config_new