Added .gitattributes

[sharwell]

Many of the files in the repository were not stored according to Git conventions. This change adds an initial .gitattributes file and re-saves all text files using the expected line endings (\n in source control, \r\n on disk when working on Windows). The presence of .gitattributes will prevent inconsistencies from being introduced in future commits, regardless of the settings being used by individual developers.

The commit which re-saves files is intentionally marked as authored by @FrancescoLogozzo. This matches the original commit to this repository and ensures git blame does not mis-attribute lines of code to me.

[yaakov-h]

FYI, git blame won't mis-attribute if you use -w to ignore whitespace.

[sharwell]

@yaakov-h CodeLens in Visual Studio does not use -w.

[sharwell]

@yaakov-h Three other places that don't use -w:

1. GitHub's Blame feature
2. GitHub's graphs page
3. Most users using Git from the command line