Eclipse Google plugin long latency fix

GWT UiBinder format and auto-complete in .ui.xml could hang the Eclipse for a while.
To avoid this, go to Preferences > XML > XML Catalog > Add...:

Key: http://dl.google.com/gwt/DTD/xhtml.ent
Key type: URI
Location: <where the file is>

AppEngine Ref Notes

Reference:
HTTPS support
Feed retrieval / OAuth