Add commons-codec library which is needed for PutHttpPassword

PutHttpPassword relies on org.apache.commons.codec.binary.Base64
without bringing the corresponding library into the set of
dependencies. Hence, building in-tree fails with

  [...]/plugins/serviceuser/[...]/PutHttpPassword.java:31: error: package org.apache.commons.codec.binary does not exist
  import org.apache.commons.codec.binary.Base64;
                                        ^

(see [1] and [2]). By adding the commons-codec dependency, the plugin
builds and loads again, when building in-tree and in standalone mode.

[1] http://builds.quelltextlich.at/gerrit/nightly/master/2015-06-25/serviceuser.jar.build.stderr.txt
[2] http://builds.quelltextlich.at/gerrit/nightly/master/2015-06-25/index.html#serviceuser.jar

Change-Id: Idf54d41ac8735665e77629abde9fc78881497f19
diff --git a/BUCK b/BUCK
index 75587f1..f31ef17 100644
--- a/BUCK
+++ b/BUCK
@@ -12,6 +12,9 @@
     'Gerrit-HttpModule: com.googlesource.gerrit.plugins.serviceuser.HttpModule',
     'Gerrit-SshModule: com.googlesource.gerrit.plugins.serviceuser.SshModule',
   ],
+  provided_deps = [
+    '//lib/commons:codec',
+  ],
 )
 
 java_library(
diff --git a/lib/commons/BUCK b/lib/commons/BUCK
new file mode 100644
index 0000000..7aafa82
--- /dev/null
+++ b/lib/commons/BUCK
@@ -0,0 +1,9 @@
+include_defs('//bucklets/maven_jar.bucklet')
+
+maven_jar(
+  name = 'codec',
+  id = 'commons-codec:commons-codec:1.4',
+  sha1 = '4216af16d38465bbab0f3dff8efa14204f7a399a',
+  license = 'Apache2.0',
+  exclude = ['META-INF/LICENSE.txt', 'META-INF/NOTICE.txt'],
+)