Grid development

 - mobile grid
Merge branch 'devel' of https://github.com/otavanopisto/muikku.git into devel
** Added initial tests for user story #20
** Added (incomplete) tests for user story #21
** Added dependencies for selenium tests into core-plugins project
** Changed QueryConnectFieldOption text to be nullable (fixes bug that
prevented users creating connect fields with non-equal number of pairs)
** Fixed a bug that caused saving null into WorkspaceSelectField to
create several field answers
Merge branch 'FTR-4' into devel
Merge branch 'devel' into FTR-18-selenium-tests
** Added more tests for user story #21