[RFC] vim-patch:7.4.186

Merging vim-patch:7.4.186

Problem:    Insert in Visual mode sometimes gives incorrect results.
            (Dominique Pelle)
Solution:   Remember the original insert start position. (Christian Brabandt,
            Dominique Pelle)

https://code.google.com/p/vim/source/detail?r=4d12112c5efae071aecbeed1a7196f18950457b3