Normalize line endings

This pull request:

* Adds BouncyCastle to the `.gitignore`.
* Adds Git line normalization configuration.
* Normalizes line endings.

It also depends on the [AutoHotkey_L](https://github.com/freenet/wininstaller-staging/pull/9) port, though cherry-picking cca0268  and e22b914, followed by running

    $ rm .git/index     # Remove the index to force git to
    $ git reset         # re-scan the working directory
    $ git status        # Show files that will be normalized
    $ git add -u
    $ git add .gitattributes
    $ git commit -m "Introduce end-of-line normalization"

([via](http://git-scm.com/docs/gitattributes))

would work too.