Update luarocks. #1018

Fix #1013.
Partial C99 cleanup of term.c #1020
vim-patch:7.4.315 #1021

Problem:    Fixes for computation of topline not tested.
Solution:   Add test. (Hirohito Higashi)

https://code.google.com/p/vim/source/detail?r=646616b6ff4defcc7bef0b198b540f6d965a8126