#2 Silk >> refresh and lazy evaluated blocks

Originally at 2015-02-27T12:14:41Z by Herbert Vojčík I think the blocks should be used differently when rendered via `<<`. Old-style `Web` package behavior of eager evaluation is easily achievable using `in: aBlock`. Therefore I think blocks should be just stored for later and evaluated (filling appropriate position where they appeared) on demand. That is, there should be `aSilk refresh` message, which should evaluate all blocks that were `<<`'d at the positions that were there at the time.