Bump NPM package versions in package.json
"grunt-contrib-copy": "~0.5.0" -> "~0.6.0"
"grunt-contrib-uglify": "~0.5.1" -> "~0.6.0"
Requires npm install to update packages and dependencies

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5532 9866e705-20ec-0310-96e7-cbb4277adcfb
Merge branch 'master' of git://bbpress.git.wordpress.org