Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Comments fixing
1) Back out "month names" -> "months names" and fix few such cases which
are wrong initially
2) "weekdays names" -> "weekday names"

Noted by: des [1]

Comments fixing
"month names" -> "months names"
typo
"Long months names (alternative)" or "in alternative form" ->
"(without case ending)"
"Long months names" -> "Long months names (as in a date)"
to not confuse developers on what purpose those sections are

Since ctime compatibility restrictions removed, use more natural date formats

Remove fixed length restrictions and padding

Convert to new locale format with md_order and without E[Ff]_fmt
Add ampm_fmt to all locales

Clear am and pm fields, add empty ampm_fmt for locales I know is not AM/PM

Use 4-digit year in x_fmt

Don't use %E* in old fields for compatibility reasons

Convert after %Ex->%Ef and %EF adding

Convert to new format

ISO8859-5 time definition