Added support for including excluded dependencies when generating POM file.

Added null check to PluginBuildSettings when no plugin dependencies are
present.
Added single dependency resolution logic to DependencyManager to support exclusion functionality when creating a POM file.
GRAILS-11036 : enhanced ValidationErrorsMarshaller to support ErrorObject.
add uaa classpath to eclipse classpath
GRAILS-11036 : enhanced ValidationErrorsMarshaller to support ErrorObject.
update resources, database-migration and cache plugin versions
fix failing tests

See https://github.com/grails/grails-core/commit/a55b85e3506664bdb88d1e9d6f025ae271ad0931
version 2.2.5
functional base url was not initialized on all code branches.

follow up to: https://github.com/grails/grails-core/pull/451
fix for GRAILS-11182 "No error handling on async request"
fix compilation error
fix for GRAILS-9905 "grails.util.Mixin does not provide access to the mixed in classes properties like the Groovy Mixin"
add generics to MixinTargetAware
fix for GRAILS-11281 "Controller can't be used as error handler"
don't fail if no WebRequest bound
allow redirects to be issues when using 'then' in returned promises
Merge branch 'baseUrl' of github.com:hauner/grails-core into hauner-baseUrl

Conflicts:
	grails-test/src/main/groovy/org/codehaus/groovy/grails/test/runner/phase/FunctionalTestPhaseConfigurer.groovy
Merge pull request #461 from memorydoor/2.3.x

GRAILS-11036 : enhanced ValidationErrorsMarshaller to support ErrorObject.
fix for GRAILS-11259 "SynchronizerTokensHolder should define serialVersionUID"
Merge branch '2.3.x' of github.com:grails/grails-core into 2.3.x