The current code base is not uniform. After some discussion,
we have chosen to go with double quotes by default.

[ci skip] Just some english and `<tt>` tags.

This will avoid a error be raised when the only input on the form is the
`collection_radio_buttons`.

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.

[ci skip]

[skip ci]

[ci skip]

This fixes the broken code block rendering and indents the examples
within the parameter list.

[Jonas Baumann & Yves Senn]

The submitted params from a select with `multiple: true` look as follows:

```
{post: {category: [""]}}

{post: {category: ["", "Category 1", "Category 2"]}}
```

This is a follow up to #1552.

This reverts commit f4a5a9ea, reversing
changes made to 7ccb4821.

Reason:

The logic is different, the first call to #option_value_selected? is for
the :selected option (the argument is the "selected" variable), the second
call is for the :disabled option (the argument is the "disabled" variable).

[ci skip]

  Example:

    = select(report, "campaign_ids") do
      - available_campaigns.each do |c|
        %option{:data => {:tags => c.tags.to_json}, :value => c.id}= c.name

content tag already knows which tags are boolean and the values that
should generate them when a truthy value is passed, so leave this logic
for it instead of duplicating when generating options tags.

as the last element of the array

A previous commit swapped out a call to select for a call to grep in
time_zone_options_for_select. This behavior actually causes the
regexp priority option to stop working.

ActiveSupport::TimeZone overrides the =~ operator which is what the
select block was using previously. Enumerable#grep
checks pattern === element and in this case that would be /US/ ===
ActiveSupport::TimeZone which does not work because
ActiveSupport::TimeZone does not supply an implicit converting to_str
method, only an explicit to_s method.

It would be impossible to provide a to_str method that behaves
identically to the =~ method provided on ActiveSupport::TimeZone
so the only option is to revert back to using select with =~.

It's faster, and doesn't force us to dup the timezones array.

Previous implementation of time_zone_options_for_select did not dup the
ActiveSupport::TimeZone.all array.  When :priority_zones were provided
the method would reject! the zones from the memoized TimeZones array
thus affecting future requests to the server.  Essentially whatever
zones were specified as :priority_zones would show up for the first
request but then disappear from the time zone options on future
requests.