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
GRAILS-10393 - dynamically generate wrapper download url
separate parameters from name when creating MimeType instances
Merge branch 'master' of github.com:grails/grails-core
Don't default to the header for the MimeType if the header is null
improve data binding error handling for unparseable request bodies
Merge branch 'master' of github.com:grails/grails-core
GRAILS-9811: Binary plugin i18n problem
+ Fix location of default messages file inside the jar so that it includes the name of the plugin, which is how it is packaged
GRAILS-9811: Binary plugin i18n problem
+ Fix location of default messages file inside the jar so that it includes the name of the plugin, which is how it is packaged
Merge pull request #392 from geedubya/master

GRAILS-9811: Binary plugin i18n problem
fix for GRAILS-10406 "Incorrect Content Type in response when Accept Header is missing for Restful Controllers"