Mineways 12.03: Add 1.21.4 Pale Garden support

[Eric Haines]

Download from here.

• Pale Garden blocks and biome added.
• Vines on the tops of blocks now export (kinda impossible normally, but let's support it). (Thanks to MiniRehvaro for reporting this problem and providing a debug world.)
• Warnings now given in TileMaker if specular (_s.png) or MER (_mer.png) texture files are encountered, which require using ChannelMixer to generate the intermediate _m/_e/_r.png files that TileMaker can process. (Thanks to Jonathan Amme for reporting this bug.)
• If the player's location is in The Nether, it is not properly recorded for viewing there, or for its equivalent Overworld position. Test which dimension the player is in and, if in The Nether, multiply X and Z by 8 to give the Overworld coordinates. (Thanks to zNightLord for filing this bug.)
• If floating groups are output for 3D printing, properly report the number of floating groups and their sizes.
• Numerous small fixes, such as trapdoor textures better applied, names of some blocks fixed, Block Test World cleanups, direct secure URLs for help menu items, etc.
• JG-RTX updated to 1.21.4.