doc txt & -h consistency: add missing options

Change those built-in commands that were attempting to exhaustively
list the options in the "-h" output to actually do so, and always
have *.txt documentation know about the exhaustive list of options.

Let's also fix the documentation and -h output for those built-in
commands where the *.txt and -h output was a mismatch of missing
options on both sides.

In the case of "interpret-trailers" fixing the missing options reveals
that the *.txt version was implicitly claiming that the command had
two operating modes, which a look at the -h version (and studying the
documentation) will show is not the case.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/commit-tree.c

@@ -15,6 +15,7 @@
 #include "parse-options.h"
 
 static const char * const commit_tree_usage[] = {
+	N_("git commit-tree <tree> [(-p <parent>)...]"),
 	N_("git commit-tree [(-p <parent>)...] [-S[<keyid>]] [(-m <message>)...]\n"
 	   "                [(-F <file>)...] <tree>"),
 	NULL