Closes #99. ldtk seems to output tiled files with no newlines in the csv
data. Tiled itself does always seem to put the newlines in however, it
can open the ldtk files so we should too.

fixes #47

Fixes #41

Because I forgot. Again. :(

 * change readme build button back since this will be a pull request

xml-rs does not seem to track rust nightly on crates.io. These changes
make sure that the master branch of this repo works with rust nightly.
Whilst Rust < 1.0 this will continue.

The crates.io version of this library will continue on a separate branch