#12 updated the template engine service constructor
#12 render all nodes, but textContent only if node does not have children
#12 bugfix
#12 improved node removal
#12 bugfix
#12 prevent deleting data _type (could cause problem when rerendering list with same data object)
#12 list UT added
#12 list factory UT added
#12 bugfix
#12 layout UT added