Use the standard library's `DateTime.parse` because it's marginally
faster and supports partial date/time strings.

Benchmark:
       user     system      total        real
old  3.980000   0.000000   3.980000 (  3.987606)
new  3.640000   0.010000   3.650000 (  3.641342)

This commit standardises the return value of `to_time` to an instance
of `Time` in the local system timezone, matching the Ruby core and
standard library behavior.

The default form for `String#to_time` has been changed from :utc to
:local but research seems to suggest the latter is the more common form.

Also fix an edge condition with `String#to_time` where the string has
a timezone offset in it and the mode is :local. e.g:

  # Before:
  >> "2000-01-01 00:00:00 -0500".to_time(:local)
  => 2000-01-01 05:00:00 -0500

  # After:
  >> "2000-01-01 00:00:00 -0500".to_time(:local)
  => 2000-01-01 00:00:00 -0500

Closes #2453

I did this because to_date gives a very unhelpful error message if you
do not pass in a correct date. In the process I think this cleans up the
 code nicely and even better it tends to be slightly faster than the
 current implementation.

Benchmark
https://gist.github.com/4440875

The Time.time_with_datetime_fallback, Time.utc_time and Time.local_time
methods were added to handle the limitations of Ruby's native Time
implementation. Those limitations no longer apply so we are deprecating
them in 4.0 and they will be removed in 4.1.

This commit adds a convenience method for converting a string to an
ActiveSupport::TimeWithZone instance using the configured Time.zone or
another passed as an argument.

This behavior mattered under Ruby 1.8, but that doesn't matter now
that we don't support it.

In addition, we don't want to proxy the #class method. A test was added
to prevent against regressions.

This documentation has been out of date.

https://www.owasp.org/index.php/XSS_%28Cross_Site_Scripting%29_Prevention_Cheat_Sheet#RULE_.231_-_HTML_Escape_Before_Inserting_Untrusted_Data_into_HTML_Element_Content
Closes #7215

The Inflector is currently not very supportive of internationalized
websites. If a user wants to singularize and/or pluralize words based on
any locale other than English, they must define each case in locale
files. Rather than create large locale files with mappings between
singular and plural words, why not allow the Inflector to accept a
locale?

This patch makes ActiveSupport::Inflector locale aware and uses `:en`` unless
otherwise specified. Users will still be provided a list of English (:en)
inflections, but they may additionally define inflection rules for other
locales. Each list is kept separately and permanently. There is no reason to
limit users to one list of inflections:

    ActiveSupport::Inflector.inflections(:es) do |inflect|
      inflect.plural(/$/, 's')
      inflect.plural(/([^aeéiou])$/i, '\1es')
      inflect.plural(/([aeiou]s)$/i, '\1')
      inflect.plural(/z$/i, 'ces')
      inflect.plural(/á([sn])$/i, 'a\1es')
      inflect.plural(/é([sn])$/i, 'e\1es')
      inflect.plural(/í([sn])$/i, 'i\1es')
      inflect.plural(/ó([sn])$/i, 'o\1es')
      inflect.plural(/ú([sn])$/i, 'u\1es')

      inflect.singular(/s$/, '')
      inflect.singular(/es$/, '')

      inflect.irregular('el', 'los')
    end

    'ley'.pluralize(:es)   # => "leyes"
    'ley'.pluralize(:en)   # => "leys"
    'avión'.pluralize(:es) # => "aviones"
    'avión'.pluralize(:en) # => "avións"

A multilingual Inflector should be of use to anybody that is tasked with
internationalizing their Rails application.
Signed-off-by: NDavid Celis <david@davidcelis.com>

AS::Multibyte are no longer required by access and filters string
core extensions.

This reverts commit fa6d921e.

Reason: Not a fan of such massive changes. We usually close such changes
if made to Rails master as a pull request. Following the same principle
here and reverting.

[ci skip]

For future reference, this is the regex I used: ^\s*#\s*\n(?!\s*#). Replace
with the first match, and voilà! Note that the regex matches a little bit too
much, so you probably want to `git add -i .` and go through every single diff
to check if it actually should be changed.

This reverts commit e8feaff6, reversing
changes made to 9adf28c0.

Reason: This broke the actionmailer tests

- access & filters don't use multibyte ext
- transliterate requires only AS::Multibyte but not multibyte ext