vim-patch:7.4.311

Problem:    Can't use winrestview to only restore part of the view.
Solution:   Handle missing items in the dict. (Christian Brabandt)

https://code.google.com/p/vim/source/detail?r=v7-4-311
Merge pull request #1720 from fwalch/vim-7.4.311

vim-patch:7.4.311