Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

. style(9)
. fix/add comments (to cover changes done thru last 20 months)
. extend monetary testcase to cover int_* values

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Add my e-mail to copyrights

Fix grouping string handling

Deal properly with "0"

Assume that "" passed as parameter also means "no grouping"
Make comparsions more clear (per style(9))

make it possible to specify grouping number from range 0..CHAR_MAX,
not only one-digit number

. Fix semantics of grouping (LC_MONETARY::mon_grouping,
LC_NUMERIC::grouping) values.
. Always set __XXX_changed flags then loading numeric & monetary locale
categories to allow localeconv() to use C locale also.