ui-log: Add "commit-sort" option for controlling commit ordering

This makes it possible to use strict commit date ordering or strict
topological ordering by passing the corresponding flags to "git log".

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
diff --git a/shared.c b/shared.c
index 3e20937..8e5ae48 100644
--- a/shared.c
+++ b/shared.c
@@ -63,6 +63,7 @@
 	ret->enable_remote_branches = ctx.cfg.enable_remote_branches;
 	ret->enable_subject_links = ctx.cfg.enable_subject_links;
 	ret->max_stats = ctx.cfg.max_stats;
+	ret->commit_sort = ctx.cfg.commit_sort;
 	ret->module_link = ctx.cfg.module_link;
 	ret->readme = ctx.cfg.readme;
 	ret->mtime = -1;