Merge changes Ia7b337e1,I7a2d8aa5,Iacc2b42b,Idf6100d1,If3fba2cc

* changes:
  init: fix copying boot properties
  toolbox: hide property implementation from watchprops
  init: verify size of property buffers passed to property_get
  init: move the system property writer implementation
  init: switch property_get to use __system_property_get