Improve Bzip2BitReader/Writer

Motivation:

Before this changes Bzip2BitReader and Bzip2BitWriter accessed to ByteBuf byte by byte. So tests for Bzip2 compression codec takes a lot of time if we ran them with paranoid level of resource leak detection. For more information see comments to #2681 and #2689.

Modifications:

- Increased size of bit buffers from 8 to 64 bits.
- Improved reading and writing operations.
- Save link to incoming ByteBuf inside Bzip2BitReader.
- Added methods to check possible readable bits and bytes in Bzip2BitReader.
- Updated Bzip2 classes to use new API of Bzip2BitReader.
- Added new constants to Bzip2Constants.

Result:

Increased size of bit buffers and improved performance of Bzip2 compression codec (for general work by 13% and for tests with paranoid level of resource leak detection by 55%).
Fix buffer leaks in DnsResponseDecoder and DnsResponseDecoderTest

Motivation:

There were two buffer leaks in the codec-dns.

Modifications:

- Fix buffer leak in DnsResponseTest.readResponseTest()
- Correctly release DnsResources on Exception

Result:

No more buffer leaks in the codec-dns module.
[#2718] Added private key decryption to JDK SSL server context.

Motivation:

Currently it is not possible to load an encrypted private key when
creating a JDK based SSL server context.

Modifications:

- Added static method to JdkSslServerContext which handles key spec generation for (encrypted) private keys and make use of it.
-Added tests for creating a SSL server context based on a (encrypted)
private key.

Result:

It is now possible to create a JDK based SSL server context with an
encrypted (password protected) private key.
More brief somaxconn logging

- Consistent log message format
- Avoid unnecessary autoboxing when debug level is off
- Remove the duplication of somaxconn path
Clean-up d9cccccbb3344997e016e6a3603126ce65705c4d

- Revert irrelevant formatting changes
- Rename resource files
  - Add .pem
  - Remove 'netty' from names
Add more utility methods to check the availability of the epoll transport

Related issue: #2733

Motivation:

Unlike OpenSsl, Epoll lacks a couple useful availability checker
methods:

- ensureAvailability()
- unavailabilityCause()

Modifications:

Add missing methods

Result:

More ways to check the availability and to get the cause of
unavailability programatically.
[#2732] HttpRequestEncoder may produce invalid uri if uri parameters are included.

Motivation:

If the requests contains uri parameters but not path the HttpRequestEncoder does produce an invalid uri while try to add the missing path.

Modifications:

Correctly handle the case of uri with paramaters but no path.

Result:

HttpRequestEncoder produce correct uri in all cases.