Update .gitattributes and fix line endings

[Flamefire]

Migrate the .gitattributes file from the SVN style attribute leftovers to Git syntax. Fix wrongly introduced CRLFs.

Migration done by:

sed -Ei -e 's/svneol=crlf#.*/eol=crlf/g' -e 's/ svneol=(native|unset).*//g' -e 's/svneol=LF#.*/eol=lf/g' -e 's/(eol=[^ ]+) eol=.*/\1/g' -e 's/ !eol//' .gitattributes
git add --renormalize .
git commit -m 'Update .gitattributes and fix line endings'