Build dev server as a java_binary

Update documentation and run_dev script to reflect reality.

Change-Id: If2468d9084d373b47c385eba3420d0ee55664750

BUCK

diff --git a/BUCK b/BUCK
index e9083fc..043aa87 100644
--- a/BUCK
+++ b/BUCK
@@ -3,6 +3,7 @@
 TYPE = 'snapshot' if GITILES_VERSION.endswith('-SNAPSHOT') else 'release'
 
 DEPS = [
+  '//gitiles-dev:dev',
   '//gitiles-servlet:servlet',
   '//gitiles-servlet:src',
   '//gitiles-servlet:javadoc',
@@ -14,7 +15,7 @@
   deps = [
     '//gitiles-servlet:servlet',
     '//gitiles-servlet:servlet_tests',
-    '//gitiles-dev:dev',
+    '//gitiles-dev:lib',
   ]
 )