IPv6 address to string rfc5952

Motivation:
The java implementations for Inet6Address.getHostName() do not follow the RFC 5952 (http://tools.ietf.org/html/rfc5952#section-4) for recommended string representation. This introduces inconsistencies when integrating with other technologies that do follow the RFC.

Modifications:
-NetUtil.java to have another public static method to convert InetAddress to string. Inet4Address will use the java InetAddress.getHostAddress() implementation and there will be new code to implement the RFC 5952 IPV6 string conversion.
-New unit tests to test the new method

Result:
Netty provides a RFC 5952 compliant string conversion method for IPV6 addresses
HTTP/2 Read Decompression Flow Control Fix

Motivation:
The current implementation of the HTTP/2 decompression does not integrate with flow control properly.
The decompression code is giving the post-decompression size to the flow control algorithm which
results in flow control errors at incorrect times.

Modifications:
-DecompressorHttp2FrameReader.java will need to change where it hooks into the HTTP/2 codec
-Enhance unit tests to test this condition

Result:
No more flow control errors because of decompression design flaw