am 19cdfa15: Merge "Add virtual destructor to please one of our compilers."
am 19cdfa15: Merge "Add virtual destructor to please one of our compilers."

* commit '19cdfa15be3c7ddf9c14ae3d0b7d94f9f37ea503':
  Add virtual destructor to please one of our compilers.

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst