Bug #620: SEO metadata fix.

Added metadata for cleaner Search Engine link descriptions.
Issue #661 SEO: Add alt attributes to media tags

Added an alt tag with contentItem.Title to img links.
Bug #586: Creation of several content items for one time
Tours thumbnails enabled
Merge branch 'master' of https://github.com/alterm4nn/ChronoZoom into toursEditor
Merge pull request #632 from javierluraschi/Fix586

Bug #586: Creation of several content items for one time
Merge pull request #664 from alex-zen/hotfix

[Hotfix] Bug #663. Timeline: Incorrect time interval for timelines which "end" is less than 1 BCE.
added new tests cases
[Hotfix] Bug #663. Timeline: Incorrect time interval for timelines which "end" is less than 1 BCE.
Merge branch 'master' of https://github.com/alterm4nn/ChronoZoom
Merge branch 'master' into bltests
Merge pull request #662 from dvoits/toursEditor

Thumbnails enabled for tourstops in the editor and for tours in the tours list.
Merge pull request #665 from a-chumagin/bltests

added new tests cases
Merge branch 'master' of https://github.com/alterm4nn/ChronoZoom
add unit test spec to unit test project
add unit test spec to unit test project

added new tests History_Of_Science_TimeLine_Borders

fix test Mouse_Marker

typo

typo
Merge branch 'master' into uitests
Tours editor: message window added
added api  support in UI tests

added new files
Merge pull request #666 from xanthics/master

 SEO fixes #620 & #661