PneumaticCraft 1.2.1

-Pressure Chamber Interface can also operate on negative pressures now.

-API: Added IEntityTrackEntry,  a way to add info to the Pneumatic Helmet Entity Tracker for modders with their own entities.

-Bugfix: Packet handling causes a memory leak.
-Bugfix: Pneumatic Door doesn’t break completely when the top part is broken.
-Bugfix: Drone ignores if a block can be placed (levers can be placed floating).
-Bugfix: Neigboring Pressure Tubes visually disconnect when another tube is transformed into a multipart.
-Bugfix: Aerial Interface causes crash when the owner relogs / chunk reloads.
-Bugfix: Pressure Chamber crashes with the new Forge (slight change in OreDictionary handling).