fixed #286 CsvReporter does not reliably close csv files/streams

All PrintStream.close() calls are wrapped in a try/catch with
exceptions being logged
Merge pull request #287 from jetztgradnet/bug-286-close-streams-reliably

fixed #286 CsvReporter does not reliably close csv files/streams
Each metrics registry should have a name.

And that should show up in JMX.
Remove all the shutdown hook nonsense.
Drop the health check singleton methods.
Drop the metrics singleton methods.
Time metrics are supposed to behave like both a meter and a histgram, containing data of both, but current Csvreporter only exports histgram data, not the meter data, fix this problem
Merge pull request #290 from yeyangever/master

Support report meter style attributes in csvReporter for timer metrics
Report at fixed rate instead of with fixed delay

Minimize reporting drift
Merge pull request #297 from jdanbrown/poll-at-fixed-rate

Report at fixed rate instead of with fixed delay
Update release notes.
Escaping the JMX ObjectName components

These components should be escaped. If they are not escaped, the ObjectName will be interpreted as a search pattern, if for example the metric name contains an asterisc
reverted an accidential code reformatting by my IDE
added constructor to InstrumentedSslSelectChannelConnector to support supplying an SslContextFactory
Merge pull request #309 from codelotus/master

Accept SslContext factory in InstrumentedSslSelectChannelConnector
Merge pull request #305 from BGehrels/master

Added escaping for JMX ObjectName components
Remove metrics-scala.
Totally revamp metrics-core.

Big new changes:

* Meter and timers no longer have units. Units will be the responsibility of reporters.
* Metrics are identified by dotted names, not quasi-ObjectNames.
* Reporting architecture has been radically simplified.
* You can register metrics not created by the registry.
* Separated health checks into their own modules.
* No more default registries.

I've pinned the other modules to metrics-core 2.2.0 to make a progressive upgrade easier.
Added metrics-healthchecks.
Bump the various modules back to 2.2 API.