Add original and last message quotes to canned responses

Otherwise, no column will be added to the %ticket__cdata table and the
ticket queue pages will be crashed (empty).

The default mode going forward will be to insert when Rich Text support is
enabled and append otherwise. To clear the draft the user can simply click
reset or delete draft icon on the bar.

Enable delete draft option on reply & internal note boxes for consistency.

If the advanced search dialog is up, avoid refreshing the page

htmLawed stripped/discarded <div> tags nested inside inline tags such as
<a>. The previous replacement engine would replace <img> tags with <div>
tags and would cause the HTML to be corrupted by htmLawed.

This patch uses <span> tags which have CSS rules to be displayed as
inline-blocks. This should stay truer to the normal sizing and placement of
the original <img> tag.

And use admin-defined site logo

This reverts commit b6b2b857.

The user should not have to step over it

If an agent submits a page via a POST (like updating settings in the admin
panel or creating a ticket) and navigates away via PJAX, if the browser
refresh button were clicked sometime later, the browser would prompt the
user to resubmit the POST data.

This patch avoids the issue by setting the browser's current URL to itself,
which magically clears the POST data.

The proper fix for the issue would be with
[Post/Redirect/Get](http://en.wikipedia.org/wiki/Post/Redirect/Get) method,
which would redirect the browser to a page it could GET after a successful
POST. Therefore a subsequent GET would reload the GET request, not the POST.
However, that would be too much of an edit for now.

References:
http://stackoverflow.com/a/6077822/1025836
http://en.wikipedia.org/wiki/Post/Redirect/Get