Update text=auto / core.autocrlf=false behavior

Git for Windows 1.9.4 changed the behavior when the text=auto attribute is specified and core.autocrlf=false.  Previous observed behavior would *not* filter files when going into the working directory, the new behavior *does* filter.  Update our behavior to match.

With Git for Windows 1.9.2:

```
C:\Temp\TestRepo> git config --get core.autocrlf

C:\Temp\TestRepo>type .gitattributes
* text=auto

C:\Temp\TestRepo>git --version
git version 1.9.2.msysgit.0

C:\Temp\TestRepo>del foo.txt

C:\Temp\TestRepo>git checkout HEAD foo.txt

C:\Temp\TestRepo>HexDump.exe /C foo.txt
00000000  61 73 64 66 0a 61 73 64  66 0a 61 73 64 66 0a 73  |asdf.asdf.asdf.s|
00000010  61 64 66 0a 66 6f 6f 0a  66 6f 6f 0a 62 61 72 0a  |adf.foo.foo.bar.|
00000020  62 61 72 0a 62 61 72 0a                           |bar.bar.|
00000028
```

After upgrading to Git for Windows 1.9.4:

```
C:\Temp\TestRepo> git config --get core.autocrlf

C:\Temp\TestRepos\Foo019>type .gitattributes
* text=auto

C:\Temp\TestRepos\Foo019>git --version
git version 1.9.4.msysgit.0

C:\Temp\TestRepos\Foo019>del foo.txt

C:\Temp\TestRepos\Foo019>git checkout HEAD foo.txt

C:\Temp\TestRepos\Foo019>HexDump.exe /C foo.txt
00000000  61 73 64 66 0d 0a 61 73  64 66 0d 0a 61 73 64 66  |asdf..asdf..asdf|
00000010  0d 0a 73 61 64 66 0d 0a  66 6f 6f 0d 0a 66 6f 6f  |..sadf..foo..foo|
00000020  0d 0a 62 61 72 0d 0a 62  61 72 0d 0a 62 61 72 0d  |..bar..bar..bar.|
00000030  0a                                                |.|
00000031
```

Sigh.