Fixes #23  - dont show create share button if no pools present.

Check if there are any pools present before showing the create share button.
Show appropriate messaging and link to the pools page if there are no pools.
Fixes #24. Service status icon legend.

Add description of the status icons on the status page.
Merge pull request #42 from sujeetsr/issue#24_service_icons

Fixes #24. Service status icon legend.
Merge pull request #41 from sujeetsr/issue#23_no_pools_share

Fixes #23  - dont show create share button if no pools present.