Changelog for BuildCraft 7.1.20

Bugs fixed:

• [#3492] Remove wasted space in packets (asie)
• [#3488] Fix Zone Planner crash in fullscreen mode (asie)
• [#3429] Fix robots sinking through bedrock if the docking station is broken (asie)
• [#3341] Fix builder not handling flowing liquid correctly in survival mode (asie)