update item and pipeline
Merge branches 'master', 'master' and 'master' of https://github.com/whitefoxx/x-crawler

Conflicts:
	xcrawler/xcrawler/feeders/utils.py
	xcrawler/xcrawler/feeders/weixin.py
	xcrawler/xcrawler/pipelines.py
	xcrawler/xcrawler/spiders/weixin_spider.py