Changed mode to all files (755 => 644)

Please, before pushing, use the following commands:
```bash
# change access flags
find . -type f -exec chmod 0644 {} \;

# convert files to Unix format (CRLF to LF)
find . -type f -exec dos2unix {} \;
``
or add it to your [git hooks](http://git-scm.com/book/en/Customizing-Git-Git-Hooks)

__For Windows Developers__:

+ Turn on saving files to Unix format in your IDE/editor, or сustomize your git so change the line endings when  pushing to LF
+ Customize your git so that he doesn't changed the access rights when it pulling/cloning the code

For more information, and to find other solutions see [git-config(1) Manual Page](https://www.kernel.org/pub/software/scm/git/docs/git-config.html)

@dypsilon maybe this should be in wiki?