DUB package file

A need has appeared to use the bindings with dub. 

Notes:
* Two additional configurations for building examples:
```
dub build --config=example-pipe-comp
dub build --config=example-pipe-decomp
echo "D is awesome" | ./xz_pipe_comp | ./xz_pipe_decomp
```
* Main configuration is `sourceLibrary`
* Posix: auto linking with liblzma
* Tested on GNU/Linux: 3.14.2-200.fc20.x86_64

P.S. If it goes, don't forget to add record to dub registry.