Find the corresponding processor for a length of len delimiter characters

Property definitions

markdown2 $ MdStaggeredDelimiterProcessor :: find_processor
	# Find the corresponding processor for a length of `len` delimiter characters
	fun find_processor(len: Int): MdDelimiterProcessor do
		for processor in processors do
			if processor.min_length <= len then return processor
		end
		return processors.first
	end
lib/markdown2/markdown_inline_parsing.nit:1279,2--1285,4