fix bug for about elements offset
remove float and table cell properties
remove span tags and relevant styles
Show intro popup to first time users. Fixes #145
Disable new user intro for apigee 127
Refactor status message. Put strings into an enum file
Update YAML Documentation link href
Update package versions
Implement "Lost Connection" error.

When backend that serves the editor is not responding, show "lost connection" error to user
Do not show "Saved" message on health check success
Clear annotations when error is fixed
Do not update if backend is not healthy
Update package versions
e-introduce Markdown support

Fixes #170 #70