Return all tags whose URI or label contain a given string.

		:param search_term: the string to search for in the URI or label names
		:type search_term: string

		:returns: a list of semantictags that match the search term
		:rtype: list of ckan.model.semantictag.SemanticTag objects

def search_by_URI(cls, search_term):
		'''Return all tags whose URI or label contain a given string.

		:param search_term: the string to search for in the URI or label names
		:type search_term: string

		:returns: a list of semantictags that match the search term
		:rtype: list of ckan.model.semantictag.SemanticTag objects

		'''
	#TODO include label search
		query = meta.Session.query(SemanticTag)
		search_term = search_term.strip().lower()
		query = query.filter(SemanticTag.URI.contains(search_term))
		query = query.distinct().join(SemanticTag.tag_semantictags)
		return query