Mark strings for translation.

The procedure [mc ...] will translate the strings through msgcat.
Strings must be enclosed in quotes, not in braces, because otherwise
xgettext cannot extract them properly, although on the Tcl side both
delimiters would work fine.

[jes: I merged the later patches to that end.]

Signed-off-by: Christian Stimming <stimming@tuhh.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
diff --git a/lib/error.tcl b/lib/error.tcl
index 16a2218..13565b7 100644
--- a/lib/error.tcl
+++ b/lib/error.tcl
@@ -9,7 +9,7 @@
 	set cmd [list tk_messageBox \
 		-icon error \
 		-type ok \
-		-title "$title: error" \
+		-title [append "$title: " [mc "error"]] \
 		-message $msg]
 	if {[winfo ismapped .]} {
 		lappend cmd -parent .
@@ -25,7 +25,7 @@
 	set cmd [list tk_messageBox \
 		-icon warning \
 		-type ok \
-		-title "$title: warning" \
+		-title [append "$title: " [mc "warning"]] \
 		-message $msg]
 	if {[winfo ismapped .]} {
 		lappend cmd -parent .
@@ -78,7 +78,7 @@
 		-font font_diff \
 		-yscrollcommand [list $w.m.sby set]
 	label $w.m.l2 \
-		-text {You must correct the above errors before committing.} \
+		-text [mc "You must correct the above errors before committing."] \
 		-anchor w \
 		-justify left \
 		-font font_uibold
@@ -99,6 +99,6 @@
 
 	bind $w <Visibility> "grab $w; focus $w"
 	bind $w <Key-Return> "destroy $w"
-	wm title $w "[appname] ([reponame]): error"
+	wm title $w [append "[appname] ([reponame]): " [mc "error"]]
 	tkwait window $w
 }