Problem:    ":let list += list" can change a locked list.
Solution:   Check for the lock earlier. (Olaf Dabrunz)

https://github.com/vim/vim/commit/1cd5e613b0d8947d52762af0e17351d5e49869de

Problem:    Various problems with locked and fixed lists and dictionaries.
Solution:   Disallow changing locked items, fix a crash, add tests. (Olaf
            Dabrunz)

https://github.com/vim/vim/commit/9bc174b69d2775b0f27ed74bf372608d18c9f3d4

Problem:    Crash when doing a range assign.
Solution:   Check for NULL poiter. (Yukihiro Nakadaira)

https://code.google.com/p/vim/source/detail?r=v7-4-541

Problem:    Whan part of a list is locked it's possible to make changes.
Solution:   Check if any of the list items is locked before make a change.
            (ZyX)

https://code.google.com/p/vim/source/detail?r=v7-4-419

Problem:    sort() is not stable.
Solution:   When the items are identical, compare the pointers.

https://code.google.com/p/vim/source/detail?r=v7-4-351

Problem:    test55 fails on some systems.
Solution:   Remove the elements that all result in zero and can end up in an arbitrary position.

https://code.google.com/p/vim/source/detail?r=v7-4-347

Problem:    sort() doesn't handle numbers well.
Solution:   Add an argument to specify sorting on numbers. (Christian Brabandt)

https://code.google.com/p/vim/source/detail?r=adc4a84f72eb44dae657af713922a6e2c1f64ae3

Move files from src/ to src/nvim/.
- src/nvim/ becomes the new root dir for nvim executable sources.
- src/libnvim/ is planned to become root dir of the neovim library.