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.
add uaa classpath to eclipse classpath
update resources, database-migration and cache plugin versions
fix failing tests

See https://github.com/grails/grails-core/commit/a55b85e3506664bdb88d1e9d6f025ae271ad0931
version 2.2.5
updated LICENSE file
JSP support shouldn't pull in the standard library by default since it is optional in JSP
Merge branch 'master' of github.com:grails/grails-core
fix for GRAILS-11282 "Content negotiation not handling multiple XML types in Accept header"
Merge branch '2.3.x'
fix failing tests
Merge branch '2.3.x'
update groovy version to 2.3.0-beta-2
fix failing tests that relied on presence on standard taglib jar
fix for GRAILS-11292 "Unable to create-app when mavenRepo credential declared in ~/.grails/settings.groovy"
GRAILS-11314 Fix @Value in unit tests
Revert some changes made by 50c5a666 to JSP tests
refactor grails-web-jsp to support standalone usage, get rid of xpp dependency
use GrailsPlaceholderConfigurer and MapBasedSmartPropertyOverrideConfigurer in unit tests