[#2215] DefaultChannelHandlerContext tasks needs to be volatile to ensure every thread only see full initialized instances
Add 'coverage' profile that generates the test coverage report
Prefer interface to implementation in type declaration

This fixes the build failure with JDK 8 due to animal sniffer error
Fix the compilation error in ConcurrentHashMapV8 + JDK8
Fix a build error

which occurred when -Pcoverage was not specified
[#2212] Skip autobahntestsuite when using -DskipTests
Fix a build error related with NPN version and JDK8
Remove a version clause added by mistake
Remove the StringCache option which was removed in JDK8
[#2219] Fix javadocs of HttpObjectAggregator to show correct handler order in pipeline
Fix a bug where DefaultPromise.setUncancellable() returns a wrong value

- Fixes #2220
- Its Javadoc says it returns true when the promise is done (but not cancelled) or the promise is uncancellable, but it returns false when the promise is done.
Fix a bug where DefaultPromise.setUncancellable() returns a wrong value

- Fixes #2220 - again
- Missing negation
Fix external Javadoc url
Make most outbound operations are cancellable

- Inspired by #2214
- It actually reduces the chance of trying to marking a cancelled promise as success again, which raises an IllegalStateException.
Make the build not fail in JDK8 until we fix Javadoc
Make most outbound operations cancellable / More robust promise update

- Inspired by #2214 by @normanmaurer
- Call setUncancellable() before performing an outbound operation
- Add safeSetSuccess/Failure() and use them wherever
Do not warn if failed to mark a void promise as success

- it's always supposed to fail.
Allow to cancel non-flushed writes
Correctly respect isAutoRead() and make it consistent across OIO/NIO
Allow to set IoRatio to 100%