refs #8432 - change foreman.url to proxy.url, support sending to proxy

1) rename foreman.url to proxy.url
2) add a parameter ```proxy.type``` (which should be set to ```proxy``` for smart proxy)
3) if ```proxy.type == 'proxy'``` then alter the url to smart proxy url.
Also, I want to ensure that ```proxy.type``` receives only "foreman" or "proxy" (or null), that's why I am checking
```ruby
 if ['foreman', 'proxy'].include? cmdline 'proxy.type'
``` 
or default it to proxy.
We can set a ```log_msg``` if ```proxy.url``` is not provided.
Thoughts?