nsqadmin: fix template compatibility for < go1.2
nsqadmin: adjust columns on node page
Merge pull request #306 from mreiferson/template_fix_306

nsqadmin: templates broken on earlier versions (< go1.2)
nsqadmin: cleanup some E2E edge cases with no topics/channels/producers
Merge pull request #310 from mreiferson/nsqadmin_minor_bugs_310

nsqadmin: minor E2E edge cases