always create mergeRemote element to ensure compatibility with version 1.5.0 of the Git plugin
removed trailing whitespace
removed trailing whitespace
Gerrit Trigger configuration should honor central gerrit configuration.

Formerly, build status values that where not set where hardcoded in
GerritContext, so even if you defined different default values in your
global gerrit trigger configuration (like CR +2 for sucessful builds),
they would be overriden.

This commit sets default value null and only creates
config entries, when value is not null.
Fixed CodeNarc violations
Release Notes: Jenkins-23318
Updated changed syntax for gerritTrigger

Also replace example with API example
Included changes to GerritTrigger config.
cleanup
Merge branch '23318-gerrit-default-build-values'
fixed violations of Println rule
fixed violations of LoggerForDifferentClass rule
fixed violations of UnusedImport rule
fixed violations of NonFinalPublicField rule, excluded the rule for test code
fixed violations of UnusedPrivateField rule
fixed violations of UnusedVariable rule
fixed violations of ClosureAsLastMethodParameter rule
fixed violations of ExplicitArrayListInstantiation rule
fixed violations of ExplicitCallToGetAtMethod rule
fixed violations of VariableName rule