Make hgk handle filenames with spaces (issue49)

contrib/hgk

@@ -2819,7 +2819,9 b' proc gettreediffline {gdtf ids} {'
 	}
 	return
     }
-    set file [lindex $line 5]
+    set tab1 [expr [string first "\t" $line] + 1]
+    set tab2 [expr [string first "\t" $line $tab1] - 1]
+    set file [string range $line $tab1 $tab2]
     lappend treediff $file
 }