decommissioned ReconfigureOnChangeFilter and replaced it with  ReconfigureOnChangeTask, added ScheduledExecutorService to Context

fest-assert is a defunct library which was replaced by assertj.

migration notes here.

http://joel-costigliola.github.io/assertj/assertj-core-migrating-from-fest.html#fest-1.4

The following unit tests were failing because they were expecting the
logger context to have package data enabled by default, but the default
had been changed to false in 8141f88e.

 * ExtendedThrowableProxyConverterTest.integration
 * RootCauseFirstThrowableProxyConverterTest.integration

This patch explicitly enables packaging data for the test's logger context.

This prevents developers from attempting to modify event's mdc map. For example by invoking

event.getMDCPropertyMap().put("k", "v");

This fixes LOGBACK-1063 by ricochet.