RTS parser: Stop preserving lack of newlines at EOF

The interaction between preserving the missing trailing newline and supporting empty fields (which is permitted for debian/control according to the Debian Policy) would require a lot of complex code for very little gain. This commit therefore removes the preserving the missing newline at EOF.

As a consequence, remove the keepends=True from most examples as it is not important (we keep it internally in the code as it should be slightly effective but not worth making big fuss about in the average case).

With this change, the code no longer generates broken output when the input includes a field that does not end with a newline and another field is added (or moved) after it.

Signed-off-by: Niels Thykier niels@thykier.net