Fix for updating swaggersocket to work with atmosphere 2.x regarding the length-delimiter filter, etc

Hi,
this PR contains the following commits:
- improve the log message at CONNECT in index_fallback.html
- some cosmetic change in echo and helloworld's index.html
The above two are just usability changes

- fix the swaggersocket's filter position to have the ...
This is the one that I mentioned in my posting in the mailing list. I talked about the strange behavior after switching to atmosphere-2.1.x from 1.1.0.RC4 regarding the way the length-prefix is added. To work around this problem, I added the prefix removal code in those scala client tests. This commit fixes the behavior so that the length prefix is only added at the top level on the entire message and not to the body content. Consequently, the adjustment in scala-client tests are reverted.

- adjust swaggersocket.js to make swaggersocket.js based samples work
I needed to make a couple of changes to swaggersocket.js so that the swaggersocket.js based echo and hellowold are working again. I would appreciate someone can review this change.

regards, aki