GROOVY-6560: Fix for escape URL in the JsonOutput (Windows path)
GROOVY-6560: Fix broken test for JsonOutput.toJson(URL)
GROOVY-6541: getAt method not found if inferred type is Integer and getAt() accepts a primitive int
Merge pull request #320 from bura/fix-json-output-escape-url

Fix json output escape url
Merge branch 'master' into jdk8