Allow components to participate to logging configuration

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Move nexus loggers configuration to CoreLogConfigurationCustomizer from logback-nexus.xml

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Make possible to unset a logger

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Move configuration logic to logback manager (from logging plugin)

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Add DEFAULT logging level that will reset level to its effective level

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Add UTs for read/write of logback-overrides.xml

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Replace LoggerContributor with LogConfigurationCustomizer in atlas plugin

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Replace LoggerContributor with LogConfigurationCustomizer in wonderland plugin

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Drop LoggerContributor and move configuration logic to log manager

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
JavaDoc

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
On unset set logger level to null instead of reconfiguration

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Add custom level propagator to handle bug in std impl with null level handling
Reload store after add/update/remove of loggers

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge remote-tracking branch 'origin/jul-level-propagator-npe-handler' into logging-improvement
programatically install the jul handler so we can use our custom impl (class-loading issues otherwise)
remove existing jul handler so we can deal with older installations.
added more logging to show what is going on
Merge pull request #207 from sonatype/logging-improvement

REVIEW: Replace LoggerContributor with LogConfigurationCustomizer & move configuration logic to logback log manager