1. Instead of setting beautiful.layout_machi. Provide `machi.get_icon()` to generate the icon.
2. Make `layout.create(name, editor)` take `name` as a function to customize tag-dependent naming.
3. Editor/switch now grabs theme settings before starting instead of loading.
1. Removed unintended global names
2. The default history file changed to `gfs.get_cache_dir() .. "/history_machi"`
3. `editor` will detect if the layout is machi before start
4. Added `machi_` prefix for machi fields in the layout objects.
Xinhao Yuan