Fixed: [ Issue 68 ] Red underline when "extensions" is present inside a message
https://code.google.com/p/protobuf-dt/issues/detail?id=68

diff --git a/com.google.eclipse.protobuf/META-INF/MANIFEST.MF b/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
index be7f077..41e5b07 100644
--- a/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
+++ b/com.google.eclipse.protobuf/META-INF/MANIFEST.MF
@@ -32,3 +32,4 @@
  com.google.eclipse.protobuf.services,

  com.google.eclipse.protobuf.util,

  com.google.eclipse.protobuf.validation

+