ACCUMULO-1835 Add -f, -x and -r docs to test/system/auto/README

Signed-off-by: Eric Newton <eric.newton@gmail.com>
ACCUMULO-1835 merge to 1.5
ACCUMULO-1857 Clean up the README to be more informative about what
users must do instead of guessing at what their distribution might do.
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT

Conflicts:
	test/system/auto/README