add table UI css, move table and tree mod to core-ui
use tree css, cleanup data explorer css
Merge branch 'feature/genericdataexplorer' of https://github.com/molgenis/molgenis into feature/genericdataexplorer
fix, show expand icons
Merge pull request #1210 from dennishendriksen/feature/genericdataexplorer

Add table UI css, move table and tree mod to core-ui
Merge pull request #1211 from jjettenn/feature/genericdataexplorer

RestController constants are added and the tests do not fail.
Merge pull request #1212 from molgenis/feature/genericdataexplorer

Merge feature/genericdataexplorer with master branch
UnknownAttributeException extends from MolgenisDataException
Add tests
Add null controls
Merge branch 'feature/genericdataexplorer' of github.com:molgenis/molgenis into feature/genericdataexplorer
Merge branch 'master' of github.com:molgenis/molgenis into feature/genericdataexplorer