Multibuilder build mode improvements
- Better (non-recursive) algorithm for finding blocks
- Shift now switches to "line" mode rather than building only one block
- On horizontal surfaces, line mode builds in a line across the player's facing direction
- On vertical surfaces, line mode builds up/down if top/bottom 15% of block face is clicked, otherwise builds left/right.
- Sharpness enchantment now adds 3 extra blocks per enchantment level, not 2
Recipe book: recipe navigation buttons are slightly more informative now