* Support Windows line endings

Previously, since the file was opened as bytes but written as text, \r\n
got written as \r\r\n, since it read in \r\n as bytes, passed through
the \r, then wrote out \r\n as text, which automatically transforms \n
into \r\n on Windows, resulting in \r\r\n. This commit fixes that.

* Improve line ending handling

* Add appveyor config

* Remove all newline translation

* Remove newline arg from binary open

* Add regression test and make requested change