vim-patch:7.4.455

Problem:  Completion for :buf does not use 'wildignorecase'. (Akshay H)
Solution: Pass the 'wildignorecase' flag around.

https://code.google.com/p/vim/source/detail?r=v7-4-455
Merge pull request #1711 from fwalch/vim-7.4.455

vim-patch:7.4.455
Remove VI option defaults. Part 1 (options a-c).
Remove VI option defaults. Part 2 (letters d-g).
Remove VI option defaults. Part 3 (letters h-l).
Remove VI option defaults. Part 4 (letters m-r).
Remove VI option defaults. Part 5 (letter s).
Remove VI option defaults. Part 6 (letters t-w).
Remove VI option defaults. Part 7 (cleanup).