First commit
Added the 'send more' link handling, see #6810

While the 'send more' link has been present in the layout,
it did not do anything since the handler has been missing
This commit introduces the proper handler.
Fixed error displaying mechanism to actually show an error

This is related to #6811, the freezing feedback submit button
was caused by a server error because the error handler
tried to display it using wrong function parameters. Now it should
not freeze, but instead tell the user what really happened on the
server side
Changed the form cleanup logic

I have previously missed that there was already a handler
present to make the 'send more requests' link work. The markup
has apparently been moved out of the #helpers block.
Now the logic is a little different - both the back button and the
'send more requests' link only change the blocks visibility, and the
form contents only get reset on a successful add request.
Made the email textarea get focus on certain events

Now the email input textarea gets focus on opening the
feedback helper, on cancelling the customization of the email
text and on pressing the 'send more requests' link.
Merged with the current wpcom repository state.
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