revision API: split parent rewriting and parent printing options

This change allows parent rewriting to be performed without causing
the log and rev-list commands to print the parents.

Signed-off-by: Adam Simpkins <adam@adamsimpkins.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/log-tree.c b/log-tree.c
index d3fb0e5..74829d7 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -231,7 +231,7 @@
 				putchar('>');
 		}
 		fputs(diff_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
-		if (opt->parents)
+		if (opt->print_parents)
 			show_parents(commit, abbrev_commit);
 		show_decorations(commit);
 		putchar(opt->diffopt.line_termination);
@@ -271,7 +271,7 @@
 		}
 		fputs(diff_unique_abbrev(commit->object.sha1, abbrev_commit),
 		      stdout);
-		if (opt->parents)
+		if (opt->print_parents)
 			show_parents(commit, abbrev_commit);
 		if (parent)
 			printf(" (from %s)",