MFC revisions 277693,278335,280382-280385,280923-280926,280931,

MFC revisions 277693,278335,280382-280385,280923-280926,280931,
280933-280939,280974-280976,281002,281009,281081,281176-281180,
281271,281275,281616 (described in-breif below):
r277693: Font fix (des)
r278335: Revert that
r280382: Whitespace, comments, and copyright update
r280383: Prevent inadvertent bootlock condition
r280384: Increase max passowrd length from 16 to 255 chars
r280385: Add missing variable hints to loader.conf(5) defaults
r280923: Whitespace
r280924: Comments
r280925: Optimize bootmsg to use fg/bg/me from screen.4th
r280926: Whitespace and cleanup
r280931: Comments
r280933: Move beastie to logo-*.4th; brands to brand-*.4th
r280934: Add remainder of supported ANSI escape sequences
r280935: Securely overwrite (zero) user input after password checks
r280936: Use equals for ASCII double frames
r280937: Solve dreaded "dictionary full" issue
r280938: Add "GELI Passphrase:" prompt to boot loader
r280939: Revert that (premature commit)
r280974: Use fg/b/me from screen.4th instead of literals
r280975: Eliminate literal escape sequences from *.4th
r280976: Use ^[[m mode-ending versus ^[[37m
r281002: Install newly added brand-*.4th and logo-*.4th files (jkim)
r281009: Revert .PATH changes to fix mips build (jkim)
r281081: Make sure forth manpages are only installed once (bapt)
r281176: Back to previous mode-endings based on feedback
r281177: Back to previous mode-endings based on feedback
r281178: Back to previous mode-endings based on feedback
r281179: Back to previous mode-endings based on feedback
r281180: Eliminate literal escape sequences from *.rc
r281271: Fix a bootlock condition if loader_version is set
NB: Commit message of r281271 has a typo, s/_logo/_version/
r281275: Re-do proper mode-endings
r281616: Add "GELI Passphrase:" prompt to boot loader

Relnotes:	Added "GELI Passphrase:" prompt to boot loader

git-svn-id: svn://svn.freebsd.org/base/stable/10@281843 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f