adding default root element to newly created reports
disabled deletion of root element
adding function isRootElement to report model
disabled making root element non-abstract
disabled dragging of root element
fixed issue #88 newly created reports should have a single abstract root element by default
some more cleanup.
adapted test to the new mandatory root element implementation
fixed exception in concept page
extended addElement action to work with parent
added root elements to taxonomy page
extended basic scenario to work and test the default root element.
Merge branch 'master' of github.com:28msec/nolap-report-editor into mandatory-root-element

Conflicts:
	app/modules/report-model.js
some more cleanup
fixed jshint warning
Merge branch 'master' of github.com:28msec/nolap-report-editor into mandatory-root-element

Conflicts:
	app/report/taxonomy/concept/concept-page.js
	tests/e2e/basic-scenario.js
fixed bug in findInTree function
fixed report model and taxonomy unit tests
Merge branch 'master' of https://github.com/28msec/nolap-report-editor into mandatory-root-element

Conflicts:
	app/report/taxonomy/concept/overview/overview.html
	tests/e2e/basic-scenario.js
Merge branch 'master' of https://github.com/28msec/nolap-report-editor into mandatory-root-element
addressing review comments part 1
Merge branch 'master' of github.com:28msec/nolap-report-editor into mandatory-root-element
addressed review comments
fixed jshint warnings