Convert Collection[String] to CURLSList

Property definitions

curl :: native_curl $ Collection :: to_curlslist
	# Convert Collection[String] to CURLSList
	fun to_curlslist: CURLSList
	do
		assert collectionItemType: self isa Collection[String] else
			print "Collection item must be strings."
		end
		if is_empty then return new CURLSList
		var primList = new CURLSList.with_str(self.first)
		var is_first = true
		for s in self do
			if not is_first then primList.append(s)
			is_first = false
		end
		return primList
	end
lib/curl/native_curl.nit:338,2--352,4