Update main root to work with GitHub Pages

Changed root from "/" to ""
Changed textures to scale using em

now, for most textures, 1em = 1 minecraft pixel (1/16 m)
font-size:1px; = 1 px per mc px
font-size:2px; = 2px per mc px
etc.
Merge branch 'em-scale'
Navigation

Added navigation and resizing controls
Language files and tooltip

Added support for language files
Added block tooltips
weird. it didn't commit everything last time...
Fix massive 3d hover faces
Saving, Loading, and NBT

Added nbt object to all blocks
Added saving to/loading from text
Items and more blocks

Added item API and added more blocks