Merge fixes from branch 'release-0.1.x'

* release-0.1.x:
  contact: Fix vCard loading
  collection: Fix potential invalid memory access
  collection: Fix build on OSX (naming collision wiht system headers)
  contact: Fix ::flags()
  constact: Restore support to add/remove contact from history
  categorizedproxymodel: Add more customization for categories
  account: Print missing field warning only once per field
  useractionmodel: Add stateful labels for hold/accept/hangup
  video: Fix more issues related to live configuration
  contact: Fix fallback collection subfolder loading
  video: Improve support for changing settings dynamically
  video: Offer a configuration proxy model