Merge pull request #405 from gregquat/2.3

Merging #401
Argument node of method "each"

The first argument of the closure of each is no longer a DomElement  instance but the Crawler instance
Merge pull request #409 from pokap/patch-1

Argument node of method "each"
Merging #408
Manually merge changes of #411
Manually merge changes of #412
Merge remote-tracking branch 'upstream/2.3' into 2.3