Encode the given string as an OID.

		>>> import snmp_passpersist as snmp
		>>> snmp.PassPersist.encode("hello")
		'5.104.101.108.108.111'
		>>>

def encode(string):
		"""
		Encode the given string as an OID.

		>>> import snmp_passpersist as snmp
		>>> snmp.PassPersist.encode("hello")
		'5.104.101.108.108.111'
		>>>
		"""

		result=".".join([ str(ord(s)) for s in string ])
		return  "%s." % (len(string)) + result