fixes #103
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
attached master of layoutmodel-renderer
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
fixes #134
Merge pull request #135 from 28msec/134

Cannot transition to abstract state 'report.taxonomy'
added a test to check that ratios are displayed correctly.