[RFC] Replace vim_strncpy with strlcpy

It must be some crazy plugin:

```c
...
2014/06/09 18:54:46 [debug @ xstrlcpy:295] 50183 - ratio: (19/200) 0.095000 (src: 0x7fedd9e54b60, dst: 0x7fff5a7a3590), res: Pl7587d7ff18005f87N
2014/06/09 18:54:46 [debug @ xstrlcpy:295] 50183 - ratio: (19/200) 0.095000 (src: 0x7fedd9e54b60, dst: 0x7fff5a7a3590), res: Pl7587d7ff18005f87N
2014/06/09 18:54:46 [debug @ xstrlcpy:295] 50183 - ratio: (19/200) 0.095000 (src: 0x7fedd9e54b60, dst: 0x7fff5a7a3590), res: Pl1f0087af18005f87N
...
```