Do not allow to export data when there a no data to export.
Related to sla #2759
adding container for children tab
adding emberjs lib
using newer version of jQuery
adding table for artifactchildren and basic js file for corresponding code
Fix bugs #2707 - [SOAP] Calculated fields value are not returned by "getArtifact(...)"
https://tuleap.net/plugins/tracker/?aid=2707

Change-Id: I7450e0c3cfcbd9c9a63718f18055f843427b34a4
begiining of ajax fetch children
Merge branch 'lostSheep' into 1693_see_all_children_and_grandchildren_of_an_artifact

Conflicts:
	plugins/tracker/include/Tracker/Artifact/Tracker_Artifact.class.php
	plugins/tracker/include/trackerPlugin.class.php
introduce tabs in artifact view
user can bookmark and switch tabs
add js unit test
insert all children given by the server
insert child in a table
display the status
display the xref
display the xref as link
tests run in browser and in console
Merge commit 'refs/changes/22/322/3' of http://gerrit.tuleap.net/tuleap into stable

* http://gerrit.tuleap.net/tuleap:
  Fix bugs #2707 - [SOAP] Calculated fields value are not returned by "getArtifact(...)" https://tuleap.net/plugins/tracker/?aid=2707
This is Tuleap 5.11.99.11
Move table generation to the js client

+ json gives the url of the artifact
+ display header of the table