Build tweaks

 - prevented the config file from being minified.
 - offloaded the js minification to a dedicated uglify task, which accepts more options than the require-js wrapper does.
 - Addded the banner to the top of the minified files.

Fix for logstash.js, updated install instructions

Merged Pull Request #484

Removed default @message from logstash dashboards

Pointer, timepicker cleanup and show _source by default in table

Fix array value delimiting in table, improve nginx config, fix indenting

Clarify error message.

Elasticsearch will throw a 404 if there is no indexes added yet, resulting in
this unclear message -- even for people that are not using any sort of proxy.

This message update should make it easier to quickly troubleshoot why the
the dialogue is popping up.

Moved dash controller to navbar. Settings for it to dashboard settings.

Templated and scriptable dashboard options

Made logstash.js look more like logstash.json. Added info notice for lack of failover and time filter

Removed extra ">" in tooltip

Switched settings panels to use tip directive