Add model to appendHtml signature so that derived class can be more specific about where they put it
addItemHtml and appendHtml are the same function and need the same fix.
Merge branch 'add-model-append'

* add-model-append:
  addItemHtml and appendHtml are the same function and need the same fix.
  Add model to appendHtml signature so that derived class can be more specific about where they put it
Release 0.1.6