WL#3616: Additional Date Translation Effects

The value of LC_TIME_NAMES affects output from
DATE_FORMAT, DAYNAME, MONTHNAME. This task suggests
additional ways to affect LC_TIME_NAMES, and
additional functions affected by LC_TIME_NAMES.

Translate AM/PM. DATE_FORMAT('%p') and
DATE_FORMAT('%r') currently return 'AM' or 'PM'.
They should return depending on LC_TIME_NAMES value.
Bar has noticed that "man 1 date" says that %p
and %P formats are blank in many locales, and
suggests that should be the case for MySQL as well.

Translate for STR_TO_DATE. STR_TO_DATE is
currently unaffected by LC_TIME_NAMES. It
should accept depending on LC_TIME_NAMES value.
Since STR_TO_DATE is the reverse of DATE_FORMAT, 
this will make round trips easier. Also,
STR_TO_DATE should be extended to accept a
locale name as an additional argument.

Extend GET_FORMAT. GET_FORMAT is currently
unaffected by LC_TIME_NAMES. Examples:
- to understand locale names:
  GET_FORMAT(DATE,'en_US')
- to skip the second argument:
  GET_FORMAT(DATE)
  which should be short for:
  GET_FORMAT(DATE,@@lc_time_names)

Add a new statement:
SHOW LOCALE [LIKE 'string'];
This would list all the locale names from
sql_locale.cc, at least. A descriptive column
(the features of the locale) is feasible too.

Allow mysqld command-line option. Usually a
server variable can be on the command line,
as the MySQL Reference Manual says:
"You can assign a value to a server system variable by
 using an option of the form --var_name=value. For example,
 --key_buffer_size=32M sets the key_buffer_size variable
 to a value of 32MB."
and
"System variable values can be set globally at server startup
 by using options on the command line or in an option file."
Therefore allow:
mysqld --lc_time_names=en_US
This has the same effect as SET GLOBAL lc_time_names='en_US'.
An additional possibility is:
mysqld --lc-time-names=en_US
Paul believes this is appropriate.

Translate day suffix. DATE_FORMAT('%D') currently
returns -- quoting the MySQL Reference Manual --
"%D Day of the month with English suffix
(0th, 1st, 2nd, 3rd, …)". It should return
depending on LC_TIME_NAMES value.

References
----------

Oracle:
http://www.stanford.edu/dept/itss/docs/oracle/10g/server.101/b10749/ch3globenv.htm#i1006894

SQL Server:
http://msdn2.microsoft.com/en-us/library/ms174398.aspx

WL#2928 (SECRET)