v4.2.2

• Fixed several issues in USDL parsing
  - implemented special cases for barcodes which don't have keys according to the AAMVA version written in the barcode
  - implemented heuristics for extraction of firstName, middleName, lastName, address, and other fields, if they can be determined based on the other fields.
• Bugfixes and tweaks in camera management code
  - fixed potential deadlock when multiple instances of PPCoordinator objects are instantiated.
  - exiting from the scanning when user presses "cancel" button is now faster
  - fixed race condition which potentially crashed the scanner when user exited and entered camera screen consecutively very fast.