Don't get blockClicked in air click PlayerInteractEvent handling

Signed-off-by: Ross Allan <rallanpcl@gmail.com>
Make PluginClassLoader threadsafe, fixes #817

Signed-off-by: Ross Allan <rallanpcl@gmail.com>
Merge pull request #821 from nallar/MC147

Avoid chunkloading in CraftEventFactory when loadChunkOnProvideRequest is enabled. Fixes #817