fix for GRAILS-11481 "GrailsDispatcherServlet throws IllegalStateException when using forward() and render()"

 Change relates to removal of sitemesh filter in GRAILS-11357.

 The filter was removed but the ContentBufferingResponse was not being removed from the request. This causes GrailsOpenSessionInViewInterceptor to not close and unbind the session. This change ensures that the wrapped response is removed from the webRequest and thus the session unbound.
Upgrade to g-d-m 3.1.1, also make it a managed dependency
revert change to make g-d-m managed, as you may want to use newer version of a plugin
update to Tomcat 7.0.54 plugin
Improve the solution that ensures the correct version of spring, groovy and grails jars by reading info from GrailsCoreDependencies
upgrade to Aether 1.0.0
GRAILS-11484 fix bug in GSP layout features with multi-line titles
Merge branch '2.3.x' into 2.4.x
optimize GroovyPageOutputStack performance
- reduce unnecessary operations
improve performance leftShift(Object) method of GrailsPrintWriter
- CompileStatic code picks this method, no call site caching like in dynamic code, so optimize the happy path
Fix currency tests for locales that don't return $ as USD symbol
Merge branch '2.3.x' into 2.4.x
fix NoneEncoder instance reference
Implement support for the dependencyManagement concept as seen in Maven http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#Dependency_Management

This allows users to enforce versions of transitive dependencies.

Fix for GRAILS-11501
Merge branch '2.4.x' of github.com:grails/grails-core into 2.4.x
Merged changes
Merge branch '2.3.x' into 2.4.x

Conflicts:
	grails-bootstrap/src/main/groovy/org/codehaus/groovy/grails/cli/fork/ForkedGrailsProcess.groovy
Merge branch '2.3.x' of github.com:grails/grails-core into 2.3.x

Conflicts:
	grails-bootstrap/src/main/groovy/org/codehaus/groovy/grails/cli/fork/ForkedGrailsProcess.groovy
Merge branch '2.3.x' into 2.4.x
don't pass null if parent process not set