Documentation update - SBB code examples - response event handling

[tzieleniewski]

References: #7
Updated documentation SBB code examples with information about 'empty' HTTP response event processing.
Updated POM files formatting.

[tzieleniewski]

References as well #9 (HTTP Servlet RA - default HTTP response status change).

[SergeyLee]

Hi Tomasz!
I'll review your PR today.
But in future please divide changes on several commits. One commit on changes formatting. Other commits on main changes.

Best regards
Sergey Lee

[SergeyLee]

I tried to build project: mvn clean install, and I have errors:

[ERROR] /home/sergeypovarnin/Projects/MobiusRepo/jain-slee.http/resources/http-client-nio/ra/src/main/java/org/mobicents/slee/ra/httpclient/nio/ra/HttpClientNIOResourceAdaptor.java:[123,22] error: cannot find symbol
[ERROR] variable httpclient of type HttpAsyncClient
/home/sergeypovarnin/Projects/MobiusRepo/jain-slee.http/resources/http-client-nio/ra/src/main/java/org/mobicents/slee/ra/httpclient/nio/ra/HttpClientNIOResourceAdaptor.java:[153,27] error: cannot find symbol
[ERROR] variable httpclient of type HttpAsyncClient
/home/sergeypovarnin/Projects/MobiusRepo/jain-slee.http/resources/http-client-nio/ra/src/main/java/org/mobicents/slee/ra/httpclient/nio/ra/HttpClientNIOResourceAdaptorSbbInterfaceImpl.java:[41,22] error: cannot find symbol
[INFO] 3 errors

If I build project without your changes it builds successful.
Now I am investigating what is wrong in pom.xml changed by you.

[SergeyLee]

Ok. I found reason: in parent pom.xml you fixed version for httpasyncclient from 4.0-beta3 to 4.0.

[SergeyLee]

I decided to leave httpasyncclient 4.0-beta3 for now.
But I will create issue for updating httpasyncclient to 4.0 or higher version.