Standards registry prototype M2832

- Implement standard registry mockups
  - todo: fix search
  - todo: add format, tags and homepage
  - todo: model details --> entity details --> add entity parent and entity subclasses
- Bugfix: show 'false' in attrubute meta data table if value is false instead of no value

![standards_registry_mockup1](https://cloud.githubusercontent.com/assets/2477186/4724321/b9eec102-594f-11e4-8653-d10589bf599d.png)
![standards_registry_mockup2](https://cloud.githubusercontent.com/assets/2477186/4724322/b9f5f454-594f-11e4-8385-1fbe06f72012.png)