Add other apps to landing page

- update descriptions
- hide disabled apps
- centralize loop that checks if an app is disabled
- fix style for conditionals
- limit to only enabled apps in the list
Merge pull request #498 from strongloop/feature/landing-descriptions

Add other apps to landing page

update descriptions
hide disabled apps

fix #475
Add contextual help directive

- fetches help given a confluence ID
- preliminary design prototype for contextual help
- build css
- add spinner to initial load
- remove test help from profiler navbar
Merge pull request #508 from strongloop/feature/contextual-help-popover

Add contextual help directive

- fetches help given a confluence ID
- preliminary design prototype for contextual help
- build css
- add spinner to initial load
- remove test help from profiler navbar

fix #672