fix(authoring): Added notifications and confirmations for saving.

SD-440
SD-443
Merge pull request #351 from eozan/authoring-save-notifications

fix(authoring): Added notifications and confirmations for saving.
fix(archive): provider keyword is changed with source in archive.

SD-502
Merge pull request #352 from eozan/archive-rename-provider

fix(archive): provider keyword is changed with source in archive.
fix(workspace): Fixed close button in widget add dialog.

SD-487
Merge pull request #353 from eozan/add-widget-close-button

fix(workspace): Fixed close button in widget add dialog.
Merge branch 'devel' of https://github.com/superdesk/superdesk-client into devel