Add http PATCH method support to rest controllers.

When issuing a PATCH request a resource should be "patched", that is updated only with the properties submitted maintaining the rest of its properties. In contrast to POST requests, the later update the whole resource regardless of any data already there.
introduce a failing test

This failing test demonstrates one of the things that is wrong with the code currently included in the PR at https://github.com/grails/grails-core/pull/495.
fix Spring version
2.4.1.BUILD-SNAPSHOT
Merge branch 'master' of github.com:cesarizu/grails-core into cesarizu-master

Conflicts:
	grails-web-url-mappings/src/main/groovy/org/codehaus/groovy/grails/web/mapping/DefaultUrlMappingEvaluator.java
Merge branch 'cesarizu-master' into 2.4.x
Merge branch '2.4.x' of github.com:grails/grails-core into 2.4.x
Merge branch 'grails-dependencies' into 2.4.x
fix inter task dependencies
reinstate signing plugin, looks like it was needed
GRAILS-11434 missing quotes in startGrails.bat
GRAILS-11430 fix NPE when reloading the same scaffolded page several times
GRAILS-11444 - improve allowedMethods

Now when a controller action invokes another controller action, the allowedMethods check will not be imposed on the second action.
GRAILS-11444 - improve allowedMethods

Now a controller action may invoke any number of other controller actions and the allowedMethods check will only be performed on the top level action.
use Groovy 2.3.2
GRAILS-11453 - allow traits to be used for controller exception handlers
Merge branch '2.4.x'

Conflicts:
	build.gradle
	build.properties
	grails-test-suite-uber/src/test/groovy/grails/util/GrailsUtilTests.java
	grails-test-suite-uber/src/test/groovy/org/codehaus/groovy/grails/commons/DefaultGrailsControllerClass2Tests.java
	grails-test-suite-uber/src/test/groovy/org/codehaus/groovy/grails/web/servlet/mvc/SimpleGrailsControllerTests.java
	grails-test-suite-web/src/test/groovy/org/codehaus/groovy/grails/web/mapping/filter/RestfulMappingsFilterTests.groovy
SimpleGrailsControllerTests no longer exists

See https://github.com/grails/grails-core/commit/66a156c80b62778a59d65e454ede5bfe18ef2008