Mer: Support more than one SDK VM in mgmt web view

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
Mer: Fix potential bug with startup-project tracking

See the result of passing project such that (project == m_project).

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
Mer: Improve "VM not responding" page in VM mgmt web view

- be more concrete about VM status
- allow to start VM directly using a hyperlink
- rephrase help text, preview button icon
- style it a bit

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>