[RFC] vim-patch:7.4.407

Problem:    Inserting text for Visual block mode, with cursor movement, repeats the wrong text. (Aleksandar Ivanov)
Solution:   Reset the update_Insstart_orig flag. (Christian Brabandt)

https://code.google.com/p/vim/source/detail?r=v7-4-407

It's strange that git thinks `test39.ok` is a binary file. Google displays the diff correctly.
Oh, silly me, thinking type casts work the *other* way.

Actually, I wonder why `linetabsize()` doesn't return a `colnr_T`... but that's not related to this patch.