Support for custom blockstate tags

Example:

setblock ~ ~ ~ stone[customtag=right]

should put a stone with a customtag tag with the value right, this can be used in resource packs to create custom blocks. you can also use it for other purposes:

For example use tags from other blocks.

setblock ~ ~ ~ stone[power=15]

will place a stone that emits a signal with a strength of 15 units