[RFC]vim-patch:7.4.309

updated for version 7.4.309
Problem:    When increasing the size of the lower window, the upper window
            jumps back to the top. (Ron Aaron)
Solution:   Change setting the topline. (Nobuhiro Takasaki)

https://code.google.com/p/vim/source/detail?r=88a6e9f33822d33b6c32db578750c6c178c63f50
@atwupack Good idea. 

I imagine @epmatsw was confused by my above comment. Looks like 02d935729f651840ee53e0cd55339c996b9789fa was the origin of the bug, but it wasn't committed yet when this PR was created.