README: remove duplicated travis badge

- routers: use new binding convention to simplify code
- templates: able to set HTTP port number in install page

The SendMail function is rewritten and has the following new functionality:
 - It is optional to skip verification of keys. The config option SKIP_VERIFY is added
 - If the port is 465, or ending on 465, the TLS(/SSL) connection is started first.

Removed trailing whitespaces with

```sh
for file in `grep -r " $" * | cut -d : -f 1 | sort | uniq | grep -v " "`; do sed -i 's/[ \t]*$//' $file; done
```

and some handwork.