treewide: remove unnecessary cache.h inclusion from several sources

A number of files were apparently including cache.h solely to get
gettext.h.  By making those files explicitly include gettext.h, we can
already drop the include of cache.h in these files.  On top of that,
there were some files using cache.h that didn't need to for any reason.
Remove these unnecessary includes.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/reflog.c b/reflog.c
index d1c3937..4e121e4 100644
--- a/reflog.c
+++ b/reflog.c
@@ -1,4 +1,4 @@
-#include "cache.h"
+#include "git-compat-util.h"
 #include "gettext.h"
 #include "object-store.h"
 #include "reflog.h"