Fix for incorrect line terminators in partials on Windows

[yasniy]

When the partial file contains Windows-slyle line terminators ("\r\n") it will not be converted into normal C-slyle "\n" for internal use. As a result the rendered file saved as text will have a broked line terminator "\r\r\n".

[robertknight]

Hello,

The change looks fine but can you add a test to check for the issue you fixed? There is one Qt 5 test that is failing but it looks like that is unrelated to the change you made.

[yasniy]

Test fails due to the way Qt 5.5 used in test handles double to string conversion. This behaviour was changed in Qt 5.7: "Added support for converting a floating point to its shortest and exact string form, without having to pre-calculate the number of digits." (What's New in Qt 5.7)

[robertknight]

I rebased on the master branch which now has CI set up.