[RFC] vim-patch:7.4.219

Merging vim-patch:7.4.219

Problem:    When 'relativenumber' or 'cursorline' are set the window is
            redrawn much to often. (Patrick Hemmer, Dominique Pelle)
Solution:   Check the VALID_CROW flag instead of VALID_WROW.

https://code.google.com/p/vim/source/detail?r=37af1e6e91bb1e8ceb89d3ba1c49a04ffd889880