mergetool: Make ECMerge use the settings as specified by the user in the GUI

When run from the command line, ECMerge does not automatically use the same
settings for a merge / diff that it would use when starting the GUI and loading
files manually. In the first case the built-in factory defaults would be used,
while in the second case the settings the user has specified in the GUI would
be used, which can be misleading. Specifying the "--default" command line
option changes this behavior so that always the user specfified GUI settings
are used.

Signed-off-by: Sebastian Schuberth <sschuberth@visageimaging.com>
Tested-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-mergetool.sh

@@ -237,9 +237,9 @@ merge_file () {
 	ecmerge)
 	    touch "$BACKUP"
 	    if base_present; then
-		"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" --mode=merge3 --to="$MERGED"
+		"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" --default --mode=merge3 --to="$MERGED"
 	    else
-		"$merge_tool_path" "$LOCAL" "$REMOTE" --mode=merge2 --to="$MERGED"
+		"$merge_tool_path" "$LOCAL" "$REMOTE" --default --mode=merge2 --to="$MERGED"
 	    fi
 	    check_unchanged
 	    ;;