updated for version 7.4.315
Problem:    Fixes for computation of topline not tested.
Solution:   Add test. (Hirohito Higashi)
Added tag v7-4-315 for changeset 646616b6ff4d
updated for version 7.4.316
Problem:    Warning from 64-bit compiler.
Solution:   Add type cast. (Mike Williams)
Added tag v7-4-316 for changeset 0fc665889e8f
Merge branch 'vim'