[Feature] Updated page header. Added new authoring edit form.

Details:
1. added header icons;
2. changed img to background-image in header;
3. replaced old authoring header buttons with new UI form
[Feature] Added navigation, refined show/close methods
[Feature] Fixed CSS and visual appearence.
[Feature] Implemented canvas edit button for timelines, exhibits and content items.

Details:
1. added svg support for web-service;
2. placed edit authoring buttions inside authoring form;
3. added clickable svg images (edit buttons) for timeline (bottom right corner), exhibit (between exhibit title and exhibit top border), content item (bottom right corner).
[Feature] Fixed console errors.
[Feature] Fixed few bugs with authoring. Fixed bug #306. Some code review fixed;

Details:
1. Fixed bug #306 - Dates in Cosmos Exhibits are displayed negative using long form;
2. fixed alert window when timeline was removed;
3. fixed exhibit's date in edit exhibit form (it was exhibit.date - exhibit.width / 2, now it's exhibit.date);
4. removed obsolete mouse handlers in authoring.ts for edit modes;
5. removed some obsolete code from authoring.ui.ts;
6. fixed few bugs with active icons in header;
7. capitalized regimes links
[Code Review Fix] Add listbox to exhibits form.
1. Async download listItem template for contentItems.
2. Renamed container2 to listItemContainer.
3. Pass listItemContainer as a parameter to exhibitForm.
[Code Review Fix] Removed obsolete code from authoring files. Fixed bug #313.fixed bug with fallbackpage.

Details:
1. Fixes for code review http://mrccodereview.cloudapp.net/ui#file:review=1147;
2. fixed bug #313. Fallback: Fallbackpage rendering is broken.
1. added scrollbars to listboxes.
2. fix bug that caused multiple duplicate content items to appear after reopening the exhibit form.
auth form fixes 1
auth form fixes 2