ISIS-537 Write the 'type' HTML attribute even for invisible buttons with placeholder

https://trello.com/c/JwALpbYI/113-bootlint-error-always-set-a-type-on-buttons
ISIS-537 Add 20px under the entity (EntityPropertiesPanel) to make a clear distinction with the row for entityCollectionsOverflow

https://trello.com/c/3LYn12tx/115-a-bit-more-space-underneath-the-ok-edit-cancel-buttons
ISIS-537 Use .input-sm for the select2 input fields.

https://trello.com/c/f60AAQps/116-tiny-adjustment-to-spacing-on-select2-drop-downs
ISIS-537 Use NotificationPanel instead of FeedbackPanel

https://trello.com/c/OB0ja10z/111-replace-all-usages-of-feedbackpanel-in-the-addons-with-notificationpanel-for-consistency-with-isis
ISIS-537 Change the name of the theme chooser cookie to be more inline with the names of the properties
ISIS-537 Use Bootstrap grid offset classes instead of empty columns. Suggested by Bootlint 0.8.0
ISIS-537: removing a TODO:mgrigorov (comments only)
ISIS-537: moved markup and CSS for LinksSelectorPanelAbstract into its subclasses (CollectionContentsLinkSelectorPanel and EntityLinksSelectorPanel).
ISIS-537: moved impl of LinksSelectorPanelAbstract (.java) to subclasses.
ISIS-537: deleting LinksSelectorPanelAbstract, no longer used.
ISIS-537: render selector panel-specific CSS to ensure that unselected views are not shown.
ISIS-537: updating comments only.
ISIS-537: collection actions now rendered in the panel header.
ISIS-537: factored out CollectionContentsSelectorDropdownPanel from CollectionContentsLinksSelectorPanel.
ISIS-537: refactoring out SelectorHelper
ISIS-537: completed factoring out of CollectionContentsSelectorHelper.
ISIS-537: mostly refactored, however hints not honoured for LinkSelectorPanel.
ISIS-537: selector drop-down now moved to EntityCollectionsPanel (ie into the panel header).
ISIS-943: Make ObjectContracts more resilient
ISIS-942: Allow auditing in transactions of entities being created/deleted.