We are generating safe strings in the paragraph, so we can escape the
tags

The previous behavior equated the sanitize option for simple_format with the
escape option of content_tag, however these are two distinct concepts.

This fixes CVE-2013-6416

Conflicts:
	actionview/lib/action_view/helpers/text_helper.rb

* replaced String concatenation by joining
* separator has default value to '', even it is nil

The separation option enable to keep entire words, lines or anything.
To split by line, like github, we can set the separation option as \n.
To split by word, like google, we can set the separation option as " ".
The radius option represent the number of lines or words we want to
have in the result.
The default behaviour is the same. If we don't set the separation
option, it split the text any where.

This options can be used to not escape the result by default.

Refactoring the truncate method to not do a sort-circuit return

This way if my text is long I don't have to do something like this:

.text
= truncate(@text, :length => 27)

 if @text.size >= 27
    = link_to "continue", notes_path, ....."")

Minor fix to the wrapper tag documentation, the options hash is the last one, added blank hash before that in the args list

using split_paragraphs method and content_tag instead of string
concatination

Allow autoloading to work as intended and avoid multiple requires.

ActionView::Helpers::TextHelper#simple_format should not change the text in place. Now it duplicates it.

ActionView::Helpers::TextHelper#simple_format should not change the text in place. Now it duplicates it.