Include xz-1.5.jar in the Onionoo release .jar file
When I started a temporary Onionoo instance for legacy/trac#20994, I noticed that the release .jar file does not contain `xz-1.5.jar`. The result is that it cannot process xz-compressed tarballs in `in/archive/`. Should we add that? If so, here's what I did, but I'm not certain whether that was the right way to add it:
```
diff --git a/build.xml b/build.xml
index 438cdc5..3c2ad5c 100644
--- a/build.xml
+++ b/build.xml
@@ -51,6 +51,7 @@
<include name="logback-classic-1.1.2.jar"/>
<include name="logback-core-1.1.2.jar"/>
<include name="slf4j-api-1.7.7.jar"/>
+ <include name="xz-1.5.jar"/>
</patternset>
<patternset id="web" >
```
But I did not check what other effects this change might have.
Oh, and we'd probably want to add these lines to the `LICENSE` file (copied from CollecTor's `LICENSE` file):
```
--------------------------------------------------------------------------
XZ binaries have been put into the public domain.
```
issue