* auto select latest version
* bash-completion comes with version 2.6.0
* version greater than 2.6.2 need submodules packed
* adjust version check order
Add experimental HTTP/TLS obfuscating as an **optional extension** of shadowsocks protocol.
More discussions can be found here: https://github.com/shadowsocks/shadowsocks-org/issues/26
As this feature is still a SIP (Shadowsocks Improvement Proposal), it's very unstable and experimental. So,
1. Don't enable it unless you know what it is.
2. Be very careful when using it in production environment.
1. Remove function `get_att_val`:
That function uses `eval` to set default values for bash variables.
Because it is very dangerous to use `eval` (someone call it the plague of shell scripting), I'd like to use the bash builtin to do that.
2. Double quote all variables to avoid unexpected expansion when using it.