Port maven_jar updates from Gerrit for new Buck version

Gerrit changes I94641c1b3 and I17aad3260.

Change-Id: Ic1511cb1d4eab1cf47b40adf6471db5ade743101
diff --git a/maven_jar.bucklet b/maven_jar.bucklet
index 4ddbafc..c909470 100644
--- a/maven_jar.bucklet
+++ b/maven_jar.bucklet
@@ -67,11 +67,17 @@
     raise NameError('expected id="groupId:artifactId:version"')
   group, artifact, version = parts
 
-  jar = path.join(name, artifact.lower() + '-' + version)
+  if 'SNAPSHOT' in version:
+    file_version = version.replace('-SNAPSHOT', '')
+    version = version.split('-SNAPSHOT')[0] + '-SNAPSHOT'
+  else:
+    file_version = version
+
+  jar = path.join(name, artifact.lower() + '-' + file_version)
   url = '/'.join([
     repository,
     group.replace('.', '/'), artifact, version,
-    artifact + '-' + version])
+    artifact + '-' + file_version])
 
   binjar = jar + '.jar'
   binurl = url + '.jar'
@@ -122,10 +128,11 @@
       out = '__' + name + '__no_src',
     )
 
+  srcdep = [':' + name + '__download_src'] if srcjar else []
   if exported_deps:
     prebuilt_jar(
       name = name + '__jar',
-      deps = deps + [':' + name + '__download_bin'],
+      deps = deps + srcdep + [':' + name + '__download_bin'],
       binary_jar = genfile(binjar),
       source_jar = genfile(srcjar) if srcjar else None,
     )
@@ -137,7 +144,7 @@
   else:
     prebuilt_jar(
       name = name,
-      deps = deps + [':' + name + '__download_bin'],
+      deps = deps + srcdep + [':' + name + '__download_bin'],
       binary_jar = genfile(binjar),
       source_jar = genfile(srcjar) if srcjar else None,
       visibility = visibility,