[GUI] Adding custom class for error messages.
Merge branch 'feature/action-feedback' of github.com:XIMDEX/ximdex into feature/action-feedback

* 'feature/action-feedback' of github.com:XIMDEX/ximdex:
  Fixes some actions flow
  Fix movenode target node list style
  Fixes move node feedback msg
  Minor style issues
  Movenode actions now has in tab flow
  Fix confirmation dialog buttons label
  Waits and tries to load again node content if datastore is already loading
[GUI]Adding scss file for welcome tab.
Minor issue
Update gitignore to ignore koala projects files
Merging origin
[GUI] Creating styles for messages and notifications. We use four types success, error, warning and info.
Merge branch 'feature/action-feedback' of github.com:XIMDEX/ximdex into feature/action-feedback

* 'feature/action-feedback' of github.com:XIMDEX/ximdex:
  Removes debug line
  Fixes a bug with search panel template in osx