Add missing options to minijail(1) manpage

We're missing -I, -L, -n, and -U. Borrowed text mostly from the '-h'
usage output, as well as some code comments, and other man pages.

Also fixup one inconsistency in the -h usage output formatting.

Bug: None
TEST=`man ./minijail0.1`; `minijail0 -h`

Change-Id: Ie5a8313486490243d3382726aed82971aad9a466
Signed-off-by: Brian Norris <briannorris@google.com>
2 files changed