GRAILS-9899: Update Protobuf
Merge pull request #391 from bobbywarner/2.2.x

GRAILS-9899: Update Protobuf
fix for GRAILS-10399 "problems downloading dependencies on newly created application"
fix for GRAILS-10400 "Grails REST is not rendering HAL+Json for Collections"
GRAILS-10319 - populate errors in GrailsWebDataBinder

This improves the functionality of uses cases where the data binder is used directly, as opposed to via DataBindingUtils.  DataBindingUtils should be treated as an implementation detail, not something that applications and/or plugins interact with directly.
fix failing test
Merge branch 'master' of github.com:grails/grails-core
fix for GRAILS-10330 "JsonRenderer Bean includes/excludes has no effect if Domain Class's properties are defined in superclass"
GRAILS-10320 - improve binding ids to persistent references
GRAILS-10364 - fix link generation

When invoking the link or createLink and specifying a url attribute, the value of the url attribute should be used for generating the link
GRAILS-10233 - locale aware number conversion support

Some relevant functional tests: https://github.com/grails/grails-functional-tests/commit/ffac2884070141afd09c61496acaa31437271ecd
GRAILS-10233 - locale aware BigDecimal and BigInteger conversion support

relevant functional tests: https://github.com/grails/grails-functional-tests/commit/da4b97effd490202e23fce95fd02a94280dc265e
GRAILS-10397 - improve how null is bound to persistent references
restored _GrailsPlugins.groovy for backwards compatibility
whitespace, cleanup
GPSCAFFOLD-61 added null checks, made html and rest responses consistent
fix for GRAILS-10402 "NullPointerException in Restful resource"
update scaffold plugin to 2.0.0.RC2
updated Hibernate plugin versions
up version to 2.3.0 RC2