strings: Add new detachable UI strings

This patch adds a bunch of informative/guidance strings for the
detachable UI that are supposed to help users who don't know what
they're doing select the right (safest) option.

Also add the '/' character to the font since we'd like to use that to
draw pagination on the language menu.

BRANCH=None
BUG=None
TEST=Together with depthcharge.

Change-Id: I7f812590d2582c684fa2cdd0c07f82968c55b172
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/903237
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
53 files changed