[WIP] vim-patch:7.4.324

Problem:   In Ex mode, cyrillic characters are not handled. (Stas Malavin)
Solution:   Support multi-byte characters in Ex mode. (Yukihiro Nakadaira)

https://code.google.com/p/vim/source/detail?r=c476e0ac8b406693c3877baffa0e97ff25e59b06

- I have changed one prefix ++ operator to postfix.
- I'm not sure about the formatting of the ifdefs, maybe some adjustments will be needed there
- Does anyone know how to test this patch? Maybe there is someone on the Neovim team who uses Cyrillic characters.
@oni-link Good point. I think it is quite safe because of the `ga_grow(&line_ga, 40);` in each iteration. But still there should be a better way to handle setting values after the end of the array. Wouldn't it be an idea to replace all places with

```
p = (char_u *)line_ga.ga_data;
p[line_ga.ga_len] = NUL;
```

or similar constructs with

```
GA_APPEND(char_u, line_ga, NUL)
p = (char_u *)line_ga.ga_data;
```
What do you think?