3631: First version of 'Open in GeoGebraTube' dialog. Currently load a page from test.geogebratube.org:8080

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29320 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Ticket #3703: implementing close "X" buttons in views (dock panels)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29321 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e