Made the feedback form react to browser window resizes

This is related to #6746, the textarea doesn't get resized
when the window is resized, so the feedback button gets lost
in an unscrollable space.
Changed the embedded styles to follow the coding standards

No values have been changed, only moved around and indented properties.
Added indentation to the feedback form HTML layout code.
Removed excess padding to save some room on smaller screens or resized windows.
Merge commit '6885d6d' into wpcom

Conflicts:
	feedback-form.tpl.php
Added an error message when there is no feedback text
Replaced the html entities with apostrophes in email texts

Using HTML entities has been introduced in rev 86020 along with some
other i18n improvements. While it has worked well for strings to be
used in HTML, it failed to work for emails. Now the apostrophe entities
are replaced by actual apostrophes.
Made the feedback form use separate interchangeable screens

This is done in order to make the 'thank you' message be more
noticeable to the user - previously it was hard to notice that
the text has changed
Made the feedback helper behave differently on small screens

In #6746 it was noted that on small screens the feedback form
occupies all screen space and doesn't let you read the actual
post you need to leave feedback for. This commit makes the
form appear in minimized state for narrow screens and adds
controls that allow the user to maximize and minimize the form
at his/her will.
Added the user name instead of an email if such a user exists

Also added some styling and changed the position of the links block
along the way.
Redistributed the contents of the feedback container header

Moved the date next to the author name, changed the links to buttons and inputs for easier manipulation.
Added the missing feedback text to avoid empty blocks.
Moved the templates into a subfolder to later break them down into smaller pieces.
Moved template, JS and CSS files to separate folders

While some files have been split, like the feedback-form.tpl.php file,
the logic remains the same, no significant changes have been made. The
only exception is that the rtl.css file has been deleted, because it
is outdated and has been replaced earlier by what is now css/writing-helper-rtl.css
Fixed the meta box display for the single column interface.
Split the meta box template code into three parts to make it more manageable.
Moved the feedback table code into a separate partial

This is done to later use the table code separately without
its wrapping elements.
Changed the feedback helper displaying logic

Before if some feedback or even some shared links were present
for the post, the feedback helper was being shown even if the post
was already in the published state. This exposed the controls to the user
but they were unusable. Now the controls display logic is handled separately
and the feedback is shown without them if the post is published.
Made newly added feedback requests show immediately on sending

This is achieved by including a part of the HTML layout
in the JSON response. This is what the template breakdown
into smaller pieces has been initially done for.
Fixed the feedback error behaviour and style

This is done to make the 'no content' error more obvious,
since it will not disappear until a user enters something
in the text box.