Update Makefile

[mchome#26] rest workaround for JLU

mchome#23, add login-errno tips

update keepalive1 another implementation, mchome#22 fixed

add a common header file

fix a retry logic on dhcp version

fix up ror array shifting problem & correct typo

enlarge username & update logging position

add bindip argument to indicate ip binding. (mchome#14)

update README