#1968 - Improve album cover generation/removal/etc.
- Added stanza to Item_Model::save that handles when cover id is null.
- Added logic to graphics::generate to copy/convert album cover thumbs from their item thumbs to ensure they're always jpg, and eliminate the possibility that we copy/convert a dirty thumb.
- Redirected other places in code where we want to do one of the above two things to use these two functions instead (gallery_event::item_updated_data_file, item::make_album_cover, item::remove_album_cover).
- Improved validation in Item_Model so only albums can have covers and all covers must be non-albums.
- Added unit tests to Graphics_Helper_Test.
Protect admins from themselves - in case an admin changed the
watermark.name setting to something terrible by accident via Admin >
Advanced, we'll just use the basename.  Fixes #1977.
Merge branch 'master' of github.com:gallery/gallery3
Automated update of .build_number to 310 for branch master
Last update: 28cd0ad2c13fec256c4a0f162ec7b552eb88d66c (3 commits ago)
Follow-on to 1e4d75c12072b49c3469f18af13bcf3439afc6b0 for #1975.
Create a siblings() function which pulls together the siblings_callback
function and makes it a more palatable API.
Merge branch 'master' of github.com:gallery/gallery3
Automated update of .build_number to 311 for branch master
Last update: 28cd0ad2c13fec256c4a0f162ec7b552eb88d66c (5 commits ago)
Merge pull request #112 from shadlaws/fix_1968

#1968 - Improve album cover generation/removal/etc.
Automated update of .build_number to 312 for branch master
Last update: 0ab40de11d65476454d4bf1129916a6856001002 (1 commits ago)
When changing the album cover, find and retarget any other albums which were using the old item as their album cover.  Fixes #1978.
Automated update of .build_number to 313 for branch master
Last update: 12ea6ad642c0e84fe67f1324f8fa00c9534e7aa5 (1 commits ago)
Actually disable the "make album cover" option when the item is already the album cover.  Fixes #1979.
Merge branch 'master' of github.com:gallery/gallery3
Automated update of .build_number to 314 for branch master
Last update: 12ea6ad642c0e84fe67f1324f8fa00c9534e7aa5 (3 commits ago)
Support additional where tuples in ORM_MPTT::parents.  Fixes #1980.
Follow-in to cff1e76e8da2055f9faf7449222b43a686014b1c for #1978
Restrict which album cover ids we swap over to the hierarchy of the
current album, otherwise we can wind up in sticky situations with
hierarchical album cover chains.

Eg, you have a hierarchy like this:

root -> A1 -> A2 --> A3 -> P1
                     A4 -> P2

P1 is the album cover for its entire hierarchy.  But then you
swap A2's album cover for A3 making this:

root -> A1 -> A2 +   A3 -> P1
                 \-> A4 -> P2

Since A1, A2 and A3 all had P1 as their album cover item id.  Now
we're swapping it over to P2 but we want to leave P1 as A3's album
cover item id.  So only look at A4's hierarchy and ignore its peers.
Automated update of .build_number to 315 for branch master
Last update: fc82f56f4b3c91ac1ceee426f477b256918636f8 (2 commits ago)
Merge remote-tracking branch 'upstream/master'
Use ->siblings() instead of ->parent()->children()
update greydragon