Restore the Description field to the media UI in 3.5.

We tried in vain -- a noble but ultimately failed effort -- to reduce the number of fields for attachments from four (title, caption, alt, description) to one (caption for images, title otherwise). Alternative text needed to stay for accessibility reasons, of course.

Eventually title returned due to heavy plugin reliance. Description is too used by too many plugins (often times incorrectly -- the caption is more likely the proper field), hence its less-than-triumphant return today.

Version 3.5 has tried to streamline media in a number of ways. Removing fields may have been too much at once, as it forced not only a user interface change, but a paradigm change as well.

Finally, on upload we populate the description field with IPTC/EXIF captions, rather than the caption field. See #22768, this should be fixed. For now, Description stays.

This commit also restores 'Title' attribute editing to the main tab of the Edit Image dialog. The "Title" field no longer populates title attributes for <img> tags by design (for accessibility and other purposes, see #18984). So, here is a more obvious 'workaround' for the tooltip community.

Finally, this:
 * Cleans up the post.php attachment editor, including by showing a prettier form of the mime type.
 * Enables plugins to specifically hide attachment_fields_to_edit from either post.php (where you can create meta boxes) or the modal (which you may not want to clutter), for compatibility reasons.
 * Hides the 'Describe this file...' placeholder when a field is read-only in the modal.

props nacin, helenyhou.
fixes #22759.



git-svn-id: http://core.svn.wordpress.org/trunk@23083 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.5-RC3-23084.

git-svn-id: http://core.svn.wordpress.org/trunk@23084 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Do not alter the body's overflow attribute when the media modal is opened. Fix image insertion in the visual editor in Firefox. props azaozz. fixes #22765.


git-svn-id: http://core.svn.wordpress.org/trunk@23085 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add hidden fields via attachment_fields_to_edit to the existing compat output. props nacin. fixes #22769.


git-svn-id: http://core.svn.wordpress.org/trunk@23086 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Restore captions for non-image attachments. see #22759.



git-svn-id: http://core.svn.wordpress.org/trunk@23087 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix branchhing in edit_post() where attachment_fields_to_save would only run when the alt text was sent. It should run whenever an attachment is saved. props sc0ttclark. fixes #22774.



git-svn-id: http://core.svn.wordpress.org/trunk@23088 1a063a9b-81f0-0310-95a4-ce76da25c4cd
New method of managing media selections. There is now a "master" selection in the background. props koopersmith. fixes #22725

* This especially helps when you switch between insert/gallery and have non-images selected (as galleries don't support non-images).
* The views now act as filters on the "master" selection, instead of having their own selections that get passed around.

git-svn-id: http://core.svn.wordpress.org/trunk@23089 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Upgrade to TinyMCE 3.5.8, fixes #22755

git-svn-id: http://core.svn.wordpress.org/trunk@23090 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.5-RC3-23091. TinyMCE updated.

git-svn-id: http://core.svn.wordpress.org/trunk@23091 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add a canonical location for media frames, an alias to fetch attachments, and frame caching to custom header. fixes #22775.


git-svn-id: http://core.svn.wordpress.org/trunk@23092 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.5-RC3-23093.

git-svn-id: http://core.svn.wordpress.org/trunk@23093 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Run the attachment_fields_to_save filter even if we don't get the fields we used to get. props nacin. fixes #22774

git-svn-id: http://core.svn.wordpress.org/trunk@23094 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add the ability to click "Edit" and kick out to the advanced image editor from within the Media modal. New window, with "Refresh" offered on your return. fixes #22743. props koopersmith, nacin, helenyhou.

git-svn-id: http://core.svn.wordpress.org/trunk@23095 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Present the correct downsized image dimensions in the Media modal when inserting. Introduces a context parameter for image_constrain_size_for_editor() instead of relying on is_admin(). props jond3r, nacin. fixes #22738

git-svn-id: http://core.svn.wordpress.org/trunk@23096 1a063a9b-81f0-0310-95a4-ce76da25c4cd