addressed review comments and some cleanup of unused code
Update delete concept feature
Show presentation tree references
Merge branch 'cellfire' of https://github.com/28msec/nolap-report-editor into cellfire-d
fixed unit tests
check if concept can be made non-abstract (has no children in presentation)
Merge branch 'cellfire-report-model' of https://github.com/28msec/nolap-report-editor into cellfire-d
fixed #34
fixed jshint and unit tests
addressed review comments
some more cleanup / alignment
Merge pull request #44 from 28msec/cellfire-d

addressed review comments and some cleanup of unused code