A security release

A new alpha release for 2.4 is out a bit sooner than expected. A security issue was noticed, so you should update as soon as possible.

• Added support for checking if all entities are 'dead'
• Added (hopefully) functional support for 1.14 cats
• Added support for clearing block drops for 1.14 (closes #659)
• Fixed inventory titles not working on 1.13 and older versions; still doesn't work on 1.14 (thanks @ShaneBeee)
• Fixed a broken documentation link (thanks @MrScopes)
• Fixed leash holder throwing exceptions (closes #2157, thanks @Blueyescat)
• Fixed chat codes being case sensitive (closes #2152)
• Fixed bugs in tablist modification expression (closes #2130)
• Fixed a security issue with chat styles (closes #2198)
• Fixed spectator target support not being available (closes #2201)
• Triggers are now called events in docs