The thread_safe gem is being deprecated and all its code has been merged
into the concurrent-ruby gem. The new class, Concurrent::Map, is exactly
the same as its predecessor except for fixes to two bugs discovered
during the merge.

This can still be added to the middleware stack, but is really not
necessary.  I'll follow up with a commit that deprecates the constant

`intance` should be `instance`

`hfvalue` parts should always be percent encoded, so lets do that!

Revert "use path escaping for email addresses"

This reverts commit 21ffef38.

Due to e25fdad2, we are correctly using
path escaping for email addresses.  This commit fixes the tests to
expect path escaping.

The `url_for` methods in `actionpack` and `actionview`
now make a copy of the provided options
before generating polymorphic paths or URLs.

The bug in the previous behavior
is most noticeable in a case like:

    url_options = [:new, :post, param: 'value']

    if current_page?(url_options)
      css_class = "active"
    end

    link_to "New Post", url_options, class: css_class

- Extracted `DELIMITED_REGEX` to `delimited_regex` method and made use of  user passed `options[:delimited_regex]` if available. Changed `DELIMITED_REGEX` to `DEFAULT)DELIMITED_REGEX` to signify what it means.
- Added tests for number to delimited and number to currency in both actionview and activesupport.

Changes

Changes

`render` is the only possible source for the `plain` option.  Pulling
the conditional up to the `render` method removes far away conditionals

We don't need to pass the full hash just to pull one value out.  It's
better to just pass the value that the method needs to know about so
that we can abstract it away from "options"

Before we were changing the state of the lookup_context for the duration
of the with_layout_format block, but since we already know the formats
we can just pass it explicitly.

Related with 8d7ce0f2

Oops, I broke the build :(

Fixes the method signature of `assign_parameters` which now takes 6
arguments instead of 4. We likely will end up chaning the method
signature further so good to know this test is here.

Prevents double submission by making disable_with the default.

Default disable_with option will only be applied if user has not
specified her/his own disable_with option, whether that is in the
`data-disable-with` string form or the
`:data => { :disable_with => "Saving..." }` hash form. disable_with
will default to the value attribute.

A configuration option was added to opt out of this functionality if
the user so desires.
`config.action_view.automatically_disable_submit_tag = false`

Sometimes you need a specific break sequence while using word wrap and as today the only option we have is "\n" and is hardcoded.

With this change you will be able to specify any break sequence ("\r\n" for example) as an option.

adding proper documentation for break_sequence in ActionView::Helpers::TextHelper.word_wrap

adding some more documentation for word_wrap custom break sequence and making sure we use new hash syntax

If, doing a test like this:

```
class BugTest < ActionView::TestCase
  def test_foo
    omg
  end
```

Will raise with:
```
RuntimeError: In order to use #url_for, you must include routing helpers
explicitly. For instance, `include
Rails.application.routes.url_helpers`.
```

Thats a bit confusing, as we are not calling url_for at all.

Browsers have not been limited to two connections per host for quite
some time now. With more connections allowed, the trade-off involved in
asset host distribution isn't so clear and it becomes more important
that developers measure actual performance before and after.

Using the string version of the class reference is now deprecated when
referencing middleware. This should be written as a class not as a string.

Deprecation warning that this change fixes:
```
DEPRECATION WARNING: Passing strings or symbols to the middleware
builder is deprecated, please change
them to actual class references.  For example:
  "ActionDispatch::ShowExceptions" => ActionDispatch::ShowExceptions
```

In the `tag_options` method, strings are continuously added to the
`output` string. Previously, we concatenated two strings and added the
generated string to `output`. By adding each of the strings to
`output`, one after the other, we will save the allocation of that
concatenated string.

Benchmark:

    require 'benchmark/ips'

    sep = " ".freeze

    Benchmark.ips do |x|
      x.report("string +") {
        output = ""
        output << sep + "foo"
      }
      x.report("string <<") {
        output = ""
        output << sep
        output << "foo"
      }
      x.compare!
    end

Results (Ruby 2.2.2):

    Calculating -------------------------------------
                string +    88.086k i/100ms
               string <<    94.287k i/100ms
    -------------------------------------------------
                string +      2.407M (± 5.8%) i/s -     12.068M
               string <<      2.591M (± 7.0%) i/s -     12.917M

    Comparison:
               string <<:  2591482.4 i/s
                string +:  2406883.7 i/s - 1.08x slower

In the `tag_options` method an array is used to build up elements, then `Array#*` (which is an alias for `Array#join` is called to turn the array into a string. Instead of allocating an array to build a string, we can build the string we want from the beginning.

Saved: 121,743 bytes 893 objects

content_tag's first argument is will generate a string with an html tag so `:a` will generate: `<a></a>`. When this happens, the symbol is implicitly `to_s`-d so a new string is allocated. We can get around that by using a frozen string instead which

This change buys us 74,236 bytes of memory and 1,855 fewer objects per request.

The instrument method creates new strings, the most common action to instrument is "!render_template` so we can detect when that action is occurring and use a frozen string instead.

This change buys us 113,714 bytes of memory and 1,790 fewer objects per request.

No idea why on earth this hash key isn't already optimized by MRI, but it isn't. 💩

This change buys us 74,077 bytes of memory and 1,852 fewer objects per request.

When an unknonwn key is passed to the hash in `PRE_CONTENT_STRINGS` it returns nil, when you call "#{nil}" it allocates a new empty string. We can get around this allocation by using a default value `Hash.new { "".freeze }`. We can avoid the `to_sym` call by pre-populating the hash with a symbol key in addition to a string key.

We can freeze some strings when using Array#* to reduce allocations.

Array#join can take frozen strings.

This change buys us 86,600 bytes of memory and 1,857 fewer objects per request.